Vehicle / player question

Hello everyone.

I have a concern as far as a model I'm working on. Since it's a mech type and players can get inside, should I make the bi-ped mech a vehicle or person? What are the downsides of exporting a mech as a normal character versus exporting it as a vehicle? I'm having some problems here so there's no way to model atm.

Can a vehicle perform animations like a character?

Can a player character have contrails and such?