1. How big of a role do the Pokemon mechanics play in the game, can you capture any type of monster you run into or is it only specific monsters?
From what I've played so far it seems you can tame any of the monsters you meet in the wild.
2. With these "familiars" do you basically focus on one familiar and the rest are just sort of support? In all the gameplay I've seen it seems like everyone uses the orange dude with the sword and shield, veggy mite?
You can "main" any familiar, I've actually not been using the one you mentioned for the most part. Though something I appreciate is that even if you don't use a familiar, they get exp, so they're useful as long as they've been with you for a little while even if you haven't used them before.
3. How quickly does the game pick up, if it doesn't hook me fairly quick I probably won't even bother to play it.
it takes some time to really get up to speed, but i think it's necessary. I was probably about 6-7 hours in before it all felt pretty much open, but that could vary depending on how thorough you are. From what Brad was saying it took him something near 10 hours to get to the same point.
Hope this helps shed some light :)
At least in the first 4-5 hours, your first point is not true. Maybe that happens later in the game, but in the beginning hours, at least your first 3 familiars are hand fed to you. Also, looking at the familiar list in the Wizard's Companion, for the sake of enemy variety, I hope those are not all the enemies you run into throughout the entire game. Perhaps what you meant to say is you can tame any familiar you meet in the wild?
For OP's sake, to the second question, the biggest reason you're probably seeing everyone using Mitey is because he's the first one you get. GIven that this is the first week of release, a lot of the videos being released are likely those of early playthroughs. Also, as someone else pointed out, the game actively encourages you to swap out familiars, going so far as to penalize you via a lockout timer if you don't swap a familiar out before their countdown clock reaches zero. That sounds like a complaint, but believe me it's absolutely one of the best mechanics of the combat. It forces fun, frantic RPG combat, especially in boss fights.
To the third question, yeah, it's a JRPG. It takes a while to pick up. That said, if you enjoy Studio Ghibli's work, you really won't mind the slower pace in the beginning as it sets up the story and basic mechanics.
All that said, I'd definitely recommend checking out the demo if you can. If you were a fan of JRPG's, I'd say this is an easy buy, but given your extremely limited interest in the genre, I'd recommend playing it safe with the demo.