As far i remember, Zippo is not strong enough to thin down artist oil paint. Need to use low odour Turpentine to get similiar effect.
Well you can but the chance paint chipping is quite high unless you using lacquer paints which is the most resistant paint you can get.

Touching is fine but it when you start to pose where the problem arise. But i have to ask this first, what kind of method of painting you use, handbrush, spray can or airbrush ?

Yes, I say posing will be a problem because there are a chance that each parts rub to each other and therefore paint chipping will occur. As for handbrush painting, just make sure you do the painting in one direction to get a smooth painting surface.