1) don't know
2) if you're not confident you can do it yourself, take the bike to a shop and have them install a new key assembly. OR, there are ways to "hotwire" the bike. he may not have ever replaced the key assembly, actually. You'll have to wait and see when you get there.
3) You ARE liable for them. They vary, plan on a few hundred bucks at least.
4) HELL YES you can sue him. Take him for everything you can! Repairs on the bike, impound fees, etc etc etc. I'd even try to make him buy the bike from me (for more than it's worth) because you have NO IDEA how it was treated while he had it.
5) forget lojack, GET THEFT INSURANCE. Seems like a no-brainer after what you've been through, doesn't it?
