1. yes you can use built-in ode physics engine. or newton wrapper or nvidia physx plugin(paid).
2. yes that is made by a professional group of 3dgs users.
3. depends on who learns it. not really hard.
p.s. modelling and modelling for games are diffrent thinks, since you are a modeller i suggest you start learning from what are requieremnts of game models, optimisations, tricks etc.
Welcome aboard, good luck
