RE: New to RC cars
1. It is a good durable product, but the price can be steep. Are you looking a the brushed or brushless (VXL) model?
2. The Helion Dominus 10SC is a cheap but relatively slow 4WD SCT. Also look at Hobbyking's SCT's. Aaarma and maybe ECX make SCT's as well. These car's are brushless capable and have better support than knock-off brands such as Exceed and maybe Redcat (I haven't used Redcat but they seem to have good customer support).
3. It depends on what you plan on doing. You don't plan on racing, so what class is popular isn't important. 2WD is generally slower, with less
traction and lower top speeds but are light and nimble. They will slide more than 4WD as they are RWD. 4WD can be faster, and do better on rough surfaces.
4. I think that you can, but I don't own LiPo's or a Slash.