You shouldn't be getting a CTD when assaulting people. Did you compile from the source code, or download the game? What operating system are you using?
You can get an infinitely large squad in theory, though it'll get unmanageable. The main factor in how many recruits you can get without having a very deep hierarchy is how much juice your characters get. If you use seduction or kidnap-and-enlighten, you can bypass the normal recruit caps. Seduction has its own limit, based on the seduction skill of the person recruiting, and kidnapping has no caps. Leadership shouldn't be in the game anymore, and you don't have to worry about who you recruit in terms of eligibility to be a leader; just make sure you grab people you can use and get lots of juice for your characters.
Try to avoid recruiting so many people that it becomes a hassle to manage -- your goal should be to have enough people to carry out your strategy, rather than just having hordes. The more people you have, the easier it is for police to find your safehouses. This isn't a huge threat, but it's worth not recruiting huge amounts of fluff recruits.
Judges are recruitable, but they're less inclined to radicalism and have significantly higher difficulty.
I wouldn't sweat wisdom/heart ratio too much unless you're planning on having them on the front lines against judges, CEOs, news anchors, and the like. There's only a few enemies that can attack your character's wisdom stat, and unless you run into them (and don't have high juice) you're pretty safe.