The 335 is an awesome platform. I do not own one, but have spent alot of time learning about them b/c it will be my next car.
1.) Yes it wil accept a hitch, itll have to be aftermarket
2.) RWD is not all that bad at all in the snow. I drove the ///M3 in the snow for 2 years. Get yourself a GOOD set of snow tires, and youll be amazed at what you can power through. Just dont have a led foot when the white stuff is on the ground and youll be fine
3.) Even though that twin turbo engine hasnt been on the market all THAT long, there is already a huge tuning market for it. The #'s ppl are making with just a reflash, downpipe, and exhaust are crazy. This car is a tuners dream.
Hope that helps!
FYI, theres not too many e90 owners here. Welcome to UB tho!
I know theres TONS of 335 info over on e90 post. But wed rather have you stick around here