Hello and welcome to the world of Liberal adventure! I'll answer your questions as best as I can.
1. Depends on your playstyle. If you have a deep hierarchy, you can have more recruits (because you can distribute new recruits between more people) and you can keep the top layers huddled up in a safe place - on the other hand, a shallow hierarchy is easier to manage.
2. Alienation occurs in two flavors - "Alienated masses" means that Moderates on the site will get violent, and "Alienated everyone" means even (former) Liberals will attack you. Also, the political gains from the alienated raid are subverted, so the raid'll actually decrease your agenda! Alienation usually occurs by accidentally hitting a Liberal/Moderate with a gun, but other, more preventable ways include picking locks, breaking doors and wrecking machines with Moderates and Liberals around to see it. You can't cancel alienation during the same raid except at Cable News / AM radio, where canceling alienation is one positive side-effect for taking over the studio.
3. There are a few pre-set slogans that may occur occasionally. My favorite is "Laissez ain't fair!"
4. Whatever the character's good at, I'd say. Donations used to be extremely overpowered, but I think they're not so anymore. However, probably the best legal fundraising method is making clothes (not T-shirts, but disguises) and selling them for profit. For a skilled tailor it doubles each dollar invested.
5. You can find lots of intelligent Liberals in the Juice Bar.