1.
If you passed intending to pass partner's reopening double, +800. Declarer can't get to dummy.
If you doubled, partner will declare NT, +400.
If you bid NT yourself, -50.
2.
The layout was kind. If you invited, +400.
3.
If you doubled, I'm not sure that you could get back to the cold slam in clubs, but I'll assume you could stay out of the doomed heart slam (the defense will have two chances to get their club ruff). +650, the most common result.
If you bid 3S, +1370 for a shared top.
If you bid 2S (as I did, in a momentary brain freeze; I swear I meant to pull out 3S!), +600 in 3NT for a terrible score. I won't let you recover.
4.
I doubled 4D and partner sat, for +100 and a rotten result. I didn't really agree with partner's bidding, though I have some sympathy. I share Rainer's view that the 3NT bid must be based at least in part on a club fit, so I would have bid 5C in his shoes. If you raised clubs, +620, unless you really think you could have gotten to the cold slam; if so I won't argue! If you doubled 3D, I doubt partner would sit for it, so you might reach 5C too.