Seems a little quiet here so...
1&2... If you're watching the OAT like a hawk you may see it rise a few degrees- erratically. If you do see this, and don't spend time thinking about it, you may just have time to put the fasten seat belt signs on...
Decision to change alt would depend on severity and crossing angle- whether you're going to be stuck in it for a while. Climb/descent depends on where you are in your flight envelope- can you get to a higher level and still have adequate buffet margins in turb? Normally its descend.
3. Think this question is alluding to where there core of the jet is in relation to the overall jet turbulence- should be a diagram in those met books of yours.
4. <blank>
i'm guessing cx? good luck with it
HJ