I love/hate St. Elmo's Fire. It's a very frustrating movie and I think that's the point. It's a coming of age movie where all the characters are at the "of age" part of their lives. School is over and they are thrusted out into the real world trying to figure out what they're supposed to do. There is a great movie buried in there. I think if you cut out Dale, the woman Emilio Estevez's Kirby was pining after and combined his character with Kevin, the writer and his roommate it would fix a lot of issues. Kirby wouldn't look like a huge stalker and making him pine after Alley Sheedy instead of a random woman we don't really get to meet makes for more interesting drama. It tightens the character work/drama and keeps the friend group size a bit more manageable while sticking with the original ideas of the movie.
Rob Lowe's Billy who is stuck in college and reluctant to be a father or grow up really holds the movie for me. Everyone gives such great performances, it's just that a lot of story beats feel so disconnected. The way he weaves back and forth really makes him feel like the glue of the film.