Can a chariot make a spin move and attack?
If so, can I give the rear section of a chariot a move action?

Yes, but if you're already in base contact with an opposing figure you'll need to make a break roll to change facing.

I was looking at the War Wagon and had a thought (I'm being nice to it, it's a long way from home..;) ). If an opposing fig is B2B with say the side, and I roll a successful break, can the front section use the move-and-attack option of Charge? I can see this both ways:
1-An opposing fig was B2B so the figure can't use the SA this way.
2-The opposing fig wasn't B2B with that section, so I can.

Number 2 is correct.