As for characters and how I'd rank them
1: Barret the baddass. I think of all the characters he's the most multifaceted. He can be the goofy comic guy, but also the first guy to resort to lethal violence and him meaning it rather than it being a goof. The one seemingly the least respected by the group(aside from Caith) but also the one who always seems to slide into the leadership role whenever Cloud is incapacitated, as he should since he was the leader before Cloud. It helps that his primary conflict is with Shinra who are vastly more interesting than Sephiroth
2: Aerith is just great. The game sells her so much as this pure mani pixie dream girl that its always really fun when she reveals she's actually goofy, bratty and has a rough and agressive side to her. The contrast makes her really appealing.
3: Cloud. The contrast between the cool stoic merc he fails to be, and the dorky boy he actually is makes for a really fun and likable character. Both funny and rather pitiable. He's an easy character to root for. And its always nice character building when Cloud lets the act fall completely and acts like himself.
4: I have nothing bad to say about Tifa but actually nothing all that good either. She's just fine in all areas. Perhaps a bit more so in the chest area. She's kind, inoffensiveness and a little bland. I guess what I like most is that her and Cloud's childhood friendship was actually really superficial and that despite being the only links to each others past they don't know each other very well.
5: I like Nanaki. Like Cloud the contrast between the person he tries to be and the baby boy underneath is a very nice basis around his character. His problem is more that he's a bit removed from everyone and everything. He's got no prior bonds with characters aside Hojo and he's always a bit at the sidelines in the present. His sideplot with the Gii and Cosmo canyon is nice but also kinda removed from Shinra and Sephiroth
6: I don't dislike Yuffie. She can be a brat and not in the lovable sense but I think that at charm. At times. At other times I think she should dial it down a notch. I also think she and her materia also risk becoming a tad too much of a ''fatesawakening character'' as the cool Fire Emblem guys say. In short her gimmick is a bit too much a part of her
7: Caith Cid is a bit awkward. Love the accent but I don't really see much place for him. He's the cute mascot character but Yuffie and to some extend Barret and Red already have that role claimed. Yeah I know who he is but its too soon for that plotpoint to really pay off. Caith also has a scrapped dark side from the original which's absence seems notable
As for the villains
1: The (non Reeve) Shinra executives are a perfect blend of goofy and really evil. Except Palmer who's just a jolly guy. Their comedic manners make them lovable without downplaying their completely evil behavior. The idea that corporate executive are kinda self obsessed morons is also rather topical
2: The Turks are fun. Its refreshing to have people who's villainy is just a job and who are perfectly normal people off the clock. That said the game does try to have its cake and eat it too with them treating the Turks this way even after they committed outright mass slaughter in Midgar.
3: Quite frankly I prefered Rufus's dad. He seemed to have more aura despite the game selling Rufus as his more competent replacement. Still he's a fine rival to Cloud and seems very much on the ball.
4: Don Corneo is a fun filler villain. Also a good combination of vile and funny. Not great, but not bad either
5: Sephiroth is supremely boring, barely in the game and attached to the multiverse plotline that's the least interesting factor of the game. He's a failure. Unlike Cloud he didn't get rehabilitated from the post FF7 days. Its a shame because Flashback Sephiroth was pretty great. If at least some part of this persona remained rather than everything about him being about bullying Cloud he might have amounted to something.