Palmer is head of the Shinra Space Program. He was responsible for helping Cid get his rocket off the ground...too bad the rocket didn't go very far off the ground. Due to Cid's failure, there have been major budget cuts to the Space Program and Palmer would like to see some of that money come back (so he can pocket most of it). He's also a very cowardly weasel. See how he reacts when you find him near President Shinra's corpse. Called "Fat Man Palmer" by Cid, he enjoys tea...with lots of lard. You do actually get to fight him. He tries to stop you from borrowing Cid's plane, the Tiny Bronco. His actions are mostly comical, though. Just plaster him with your strongest stuff and he'll go away.
If there was any character in any RPG that could define the term "bitch," it's her. She's the head of Shinra's Weapons Development Department. All she does is laugh and plot along with her buddy, Heidigger. She thinks Tifa's a stuck up bitch, but I think she needs to look in the mirror. Well, she and Tifa duke it out in a little slapping match (not a real fight). Just slap her as she's raising her hand you'll get your smacks in before she gets hers. You later fight her and Heidigger when they're trying out their new weapon, the Proud Clod.
Heidigger's in charge of the military division and special forces, so you can see why he's buddy-buddy with Scarlett. He oversees the army, navy, air force, Soldier, and The Turks. His laugh is about as obnoxious as Scarlett's and they think they make a great team. Well, wait until you burst their bubble. Shortly before you fight Dr. Hojo, Scarlett and Heidigger will attack you with their secret weapon, Proud Clod. It's this giant robot with a gun on it's head. Now, since you fight Proud Clod this late in the game, you should have Knights of the Round and Mime. Have one person cast Knights, have another Mime it and have your third character sit back and enjoy the view of the major ass-kicking you're giving it. If you don't have Knights, yet, Proud Clod's a little trickier and I guess you should read this anyway since Proud Clod is also the last enemy in the Special Duel in the Battle Arena and you could posibly lose the use of your materia in there, which includes Knights. He has two parts, the main body and the armor. Take out the armor first since it has less hit points, then pummel the main body. Don't let up. If he starts to get on his knees, that doesn't mean he's weakened. That means he's about to shoot that laser on his head at you! Get ready to heal before he does this and if your characters are low in HP, heal them BEFORE he hits you.
Dr. Hojo is the very model of a modern mad scientist. He orchestrated The Jenova Project and was responsible for Sephiroth. That alone, should make you want to kill him, but let's not forget how he attempted to experiment on Aerith and Red XIII. And, of course, when the rest of the Shinra higher-ups are actually trying to stop Sephiroth from destroying the world (how noble of them), he's determined to HELP his "son." What a quack. Anyway, you encounter him 3 times during the game. First, you rescue Aerith and Red XIII from him in the Shinra Building where he sics some weird poison creature on you (it's easy, just don't use Poison on it!). When next you meet, he's in Costa Del Sol, soaking some rays, slapping back drinks, and chillin' with the babes. If you want to actually see him, don't rest in the inn as soon as you reach Costa Del Sol. Go straight to the beach and you can have a little chat with him. Finally, you've gotta stop him from overloading the Midgar Mako Reactors. He's gone truly nuts as not only is he helping Sephiroth, but you find that he's been experimenting with himself! Yes, he's injected Jenova cells into his own body, which mutates him into three really strange forms. This is the last thing you do on Disc 2, so you should have Knights of the Round and Mime by now. This makes beating Hojo a snap.
Hojo: In his first form, he looks pretty normal...well as normal as he can look, anyway. But he sics a few buddies on you, too. If you have Knights and Mime, use Knights to thrash him quickly, then wait for the next battle to Mime it. If not, just keep hitting Hojo himself and ignore his buddies. It's best to save the powerful summons for his last form, though.
Heretic Hojo: He's got twice as much HP in this form as he did before, but he's still not too hard. Just whack away at him. Once again, Mime that last Knights if you can.
Lifeform Hojo: Now, he's pissed and he'll take out his anger on your characters one by one. Make sure at least one character has a Ribbon and that character has Heal (up to Esuna). His combo attack will hit one character several times, poison him, and put him to sleep. You don't want to end up with a bunch of poisoned, sleeping characters, so take proper precautions. Of course, if you have Knights + Mime, once again, just Mime Knights and end his misery.
Reeve is head of Urban Development. So, basically, he has a better love of the city, itself. And, belive it or not, he actually CARES about people. That's something you don't find that often in Shinra, especially not this high up. But then it's not he won't resort to things like kidnapping and spying. But he isn't too thrilled about about the way Shinra's headed, so he's certainly more on your side than the rest. You never fight him and you never confront him directly, but I guess that's because he's smart enough to know that you'll kick his ass, a lesson Rufus learned really early. Still, he has a secret that won't be revealed until very late in the game...