Yes, there is damage but it is all cosmetic. Damaging a vehicle will not effect its drivability or handling.
Yes
no
I would say 20's depends on the car
no just get Driver San Fransico
you just amke it out of shapes... and a lot of time and patience
No
To unlock Jin's 350Z in Midnight Club: Los Angeles, you need to complete the "Los Angeles" mission in career mode. After finishing this mission, the car becomes available for purchase at the garage for $50,000. Be sure to have enough in-game currency to buy it, as it is one of the more sought-after vehicles in the game.
you can't actually leave your car you can but not conventionally, i.e. motorcycles and/or certain cutscenes other than that there are no possible ways to get out without cheats/mods.
no
Nope, sorry
Midnight club
well you can if you crash with a bike