These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Ho Yay: Lando needs Luke's endorsement to find a bride.
Moral Event Horizon: Thrackan, holding Han and Leia's children hostage. Also an In-Universe example, as the Corellian culture values family loyalty. This action inspires Dracmus' Mook Face Turn.
Narm: The fact that a pro-human fascist organization has the same name as a 1980s band can be amusing to read.
The Scrappy: Thrackan. Even for a villain, he's hated. The fact that he met his defeat at the hands of nine-year-old Jacen & Jaina and seven-year-old Anakin didn't exactly help to guarantee him a spot among the greatest EU villains of all time. Unlike most of his more well-regarded fellows, however, Thrackan did manage to stick around as a thorn in the heroes' side for years after these books, rather than getting killed off; he finally met his doom as the Disc One Final Boss of Legacy of the Force.
Stranger Behind the Mask: Relatively speaking. Although the group that ends up being behind everything is mentioned several times in the books, they are not an important player in the Star Wars universe. Once it became apparent another force was behind the takeover, fan speculation ranged from Pellaeon or Daala (who were both still at large at that time) to the reappearance of the Ssi Ruu (essentially giving us the Yuuzhan Vong invasion plot five years earlier). The revelation of the true culprits was underwhelming.
What an Idiot: The entire New Republic, at the very end, for simply not having Thrackan executed. He ended up returning to power twice. Fantastic work, Leia.