In Stormqueen!, the heroine ends up completely messed up because she had to use her powers to blast the besieging army with lightning. But she and her allies were in a castle on a hill, the besiegers were in the valley in tents. Two weeks of torrential rainfall would have done the job just fine.
This was before the Compact. It was probably assumed that the attackers would bring laran powers to bear against the castle before long.
In Rediscovery, Thyra is presented as the second child of Kermiac of Aldaran and Felicia Darriell, born during the events of the book. It is mentioned that Felicia's older child is a daughter (while Thyra was born without a clearly defined gender, in concordance with what is revealed during 'Sharra's Exile). I understand this book clearly has many inconsistencies when taking into account the other ones featuring some of the same characters - but those are mainly related with the general timeline. During Heritage of Hastur and Sharra's Exile, the only children of Felicia Darriell ever mentioned are Thyra, Marjorie and Rafe. So, what was the point of this extra child that was never mentioned again, not even in passing? Sure, she could have died young, but you'd figure someone (Kermiac, Kadarin, Thyra) would still remember and maybe eventually mention her.
In Exile's Song, everyone seems to have forgotten Jeff Kerwin's lineage, including Jeff himself. Mikhail identifies him as the grandson of Damon Ridenow (correct so far), son of Damon's nedestro — bastard, though not meant in a pejorative sense — daughter Cleindori (also correct) and her husband Arnad Ridenow (who?). Jeff Kerwin was identified in The Bloody Sun (published well before Exile's Song), as the son of Cleindori and her lover Lewis Lanart-Alton, the elder brother of Marguerida's grandfather Kennard Alton. In fact, Jeff's paternity is crucial to the plot of Bloody Sun; the main reason Kennard does not tell Jeff of his parentage is that he fears Jeff might try to claim Armida, displacing Kennard's sons. (It's not mentioned, but as son of Kennard's older brother, Jeff might even be able to displace Kennard himself.) And Jeff's paternity cannot have been a secret at the time of Exile's Song. In the earlier (both in terms of Darkovan chronology and publishing date) novel Sharra's Exile, Jeff identified himself as Lewis's son during a meeting of the Comyn Council.
In Exile's Song, Jeff introduces himself to Marguerida as "Damon Ridenow." According to previous books, this is not his name, even on Darkover. While his mother, Cleindori, was the daughter of Damon Ridenow, her legal surname was Aillard, for her mother's family; on Darkover, a child takes the name of the parent of higher rank, and in Comyn the Aillard outrank the Ridenow. Jeff/Damon, then, is the son of Cleindori Aillard and Lewis Lanart-Alton; the Aillard also outrank the Altons, so Jeff/Damon would have the surname of Aillard. It's suggested in The Bloody Sun that he might prefer to take his father's surname, since on Earth he was brought up to consider that proper. If he did so, he would be Damon Lanart. Finally, it's possible he might even go by the last name of his late wife, Elorie Ardais, if the Ardais outrank the Aillard (no idea). What name would he not carry? Right. Ridenow.
Arnad doesn't entirely come out of nowhere; when The Bloody Sun was originally written, Jeff's father was indeed Arnad Ridenow, and was only changed to Lewis Lanart-Alton in a later version of the book. There is still no reason for Arnad to be cited as his father in Exile's Song, decades after the revised history was put in place.
Concerning the fertility (or lack of) of the chieri and their descendants, it is mentioned that full-blooded chieri can change gender (as shown during World Wreckers) and so do not have the same sterility issues as their descendants, the emmasca (neuter) children occasionally born in families known for having a fair amount of chieri blood, such as the Ardais and Aillard. I don't think we are shown any instances of any hybrid ever displaying the ability of changing their gender (the two characters in World Wreckers who did were both full-blooded chieri). Thyra from Heritage of Hastur and Exile's Song, however, is able to get pregnant and carry a child to term, but is then said to have been emmasca at birth, that no one knew if she was male or female at first, and it was only after falling in love with Kadarin that she started considering herself as a female. She had to have actually changed from neuter to female to be able to conceive, but the problem here is that she is only one-quarter chieri (her mother is said to have been half-chieri). Sure, most of the people with chieri blood are able to conceive, but Thyra's sister, mother and daughter, for instance, despite all having a fair amount of chieri blood, were all born as females, unlike her. And in no occasion in the series has a child born as an emmasca shown to be able to have children, implying that they could never change their gender to become either a fully functional male or female. That was actually the reason why the king at the time of Stormqueen! was replaced with his cousin, as he would never be able to provide a heir to the line, and was even mentioned to have been married for many years, with not even a rumour of his wife being pregnant during that time. So...why was Thyra even able to conceive in the first place?
The entire problem with chieri gender-shifting is that it seems to be involuntary. Even with their incredible psychic powers the chieri themselves cannot control when they shift (as indicated in one scene in The World Wreckers). Thus any chieri may or may not be fully male or female even when their external form suggests otherwise. Hence they have trouble reproducing with each other, and a noticeably easier time doing it with humans (who are always one gender). However, the gender-shifting trait may persist even in those of mixed blood. It is commented that homosexuality was frowned upon in some families with a lot of chieri ancestry because: "If you lay down with a man, you may rise up as a woman!" and this had caused problems with successions in the past. This involuntary and unpredictable nature of the gender-shifting accounts for why someone could be emmasca (many chieri seem to default to this) only to later change into a male or female.
Almost as bad (or even worse) than Jeff Kerwin's confusion over his own lineage is the example of Darius-Mikhail Zabal in the recent novel The Alton Gift. It had been previously established that Jeff Kerwin Jr.'s mother Dorilys Aillard (aka Cleindori Aillard) had been the last remaining female from the main Aillard line. Since Jeff was her only child and had no surviving children of his own, and the Aillard family follows a matrilineal succession, Callina Lindir-Aillard, a cousin from a collateral lineage, became the new Head of the Aillard Domain (as it was mentioned several times in Heritage of Hastur and Sharra's Exile). Callina died during the events of Sharra's Exile, though, and so did her younger sister Linnell, leaving their half-sister Marilla as the only surviving Aillard female. Marilla then became the Head of the Domain, which makes sense up until this point. Her only child was a son, fathered by Dyan Ardais, who eventually became the Head to the Ardais Domain. After Marilla's death in The Alton Gift, the matter of the succession to Aillard would get tricky again - but even thought Marilla had no daughters to succeed her, it was stated that her son had many nedestro children, three of which were legitimized during this novel. One of those was a daughter, Illona Rider - sure, she was illegitimate, but after being legitimized by her father, why not make her the next heir to the Aillard Domain (or any other sister of hers that could be legitimized as well)? A granddaughter of the previous Lady Aillard would seem like a logical solution.
Instead, a distant relative, Darius-Mikhail Zabal, was brought over by one of the Towers to act as Marilla's heir. And his supposed lineage contradicts much of what was stated in previous novels. First, they claim that he was a descendant of Cassilde, the half-sister to Jeff Kerwin's mother Cleindori, mentioned above. The problem here was that Cleindori was the heir to Aillard through her mother, Jaelle, not her father, Damon Ridenow (which was the parent she shared with Cassilde!). Cassilde had no claim to the Aillard Domain whatsoever. Then, they make things even worse by saying that Darius-Mikhail is descended from Cassilde through her son Auster, known as Auster Ridenow. Auster was the son of Cassilde through the Terran Jeff Kerwin Sr., though, which was one of the main plot points in The Bloody Sun. Odd how everyone would conveniently forget that... They do say that Auster was not actually a Ridenow, but their explanation is even more preposterous, continuing the belief that Cassilde was somehow related to the main Aillard line, and that her son Auster was renamed as "Auster Ridenow" for his own protection, so that he wouldn't be assassinated like his aunt. So, we had a completely new character introduced, with a family history that makes no sense whatsoever, when they could have just use a previously existing character to solve this particular problem. It boggles the mind.