Angst? What Angst?: Averted. Characters react far more naturally and are scared or down when appropriate,but there's no excessive angsting around.
Complete Monster: Happosai, whose misdeeds were often discussed by Genma, Soun, and the Amazons before he finally appears in Chapter 26. What follows is an utter nightmare for the characters and the reader: the first thing he does is tear up Kasumi's clothing so he can ogle her, then he gropes Nabiki before attacking the group, declaring his intention of moving in with the Tendos and forcing them, the Saotomes, and their friends to be his slaves while he lives the easy life. When he was younger, he came to the Amazons' village and seduced Ku-Lon before showing his true colors by brutally raping several of her friends—driving some of them to suicide in the process—and running off with several of their sacred artifacts in the hopes of using them to satisfy his hedonism. When Ku-Lon responded by using a powerful spell to render him impotent, he retaliated by beating her near death. Years later, he attempted to mold Soun and Genma into hedonistic monsters like him, and toyed with the idea of killing them when it became apparent that he had failed. Throughout his debut appearance, Happosai revels in his pettiness and cruelty, and becomes enraged when those he intends to victimize refuse to bend over backwards to please him.
Konatsu's ugly step-family are a trio of utter scumbags who forced the poor boy through all sorts of sexual hell during his childhood. When Ryoga accidentally destroys their "tea shop", they order Konatsu to kill Ryoga and bring back his severed head, and when he fails, they kidnap Akari, Akane, and Ukyo and use them as hostages. While doing so, the trio announce their intentions of gang-raping the girls before chopping them up, or perhaps selling them into sexual slavery. When asked why they commit such horrific acts, they laugh and declare that every monstrous thing they've done—and they are well aware that their actions are sick and depraved—is simply For the Evulz.
Crossover Ship: Due to mixing both series, many ships are this. Ranma/Ami of course. Mu-Tsu/Makoto also seems to go that way.
As of Chapter 26, there is a possibility that Akane could get together with Ryo Urawa.
Damsel Scrappy: Very much averted. Akane and Usagi were pretty bad for this in canon. Here, they both are very capable of defending themselves and are not stupid enough to be lured into obvious traps.
The one time where Akane did get overpowered and taken hostage by Konatsu's ugly step-family, she's livid at herself for getting into this situation, although she admits being threatened with having all her bones broken made it a little less shameful.
Neutral Evil: Clearly Happosai's alignment. Happosai is here monstrous in that his caring for no one but himself it taken to its logical conclusion. His willingness to do whatever it takes to get what he wants, regardless the consequences, is shown in its whole nastiness.
Win Back the Crowd: Years of stale by-the-formula stories have left the Fuku Fic a dead field. Judging by the reviews, many see this as a breath of fresh air in this kind of crossover.