I'd bid 2D, but not feel great about it AT ALL. Can't double, but if partner has a smattering of stuff we may have game. Pass is not unreasonable, but if it isn't passed out partner will never ever ever believe you have this much. Crazed fools might try 1NT.
Over 2H, I'd pass (this is the easy part), silently (that's the hard part) cursing under my breath that I jockeyed them into a heart fit instead of 1S -3 or something, and waiting for LHO to wake up and bid 4H or something ridiculous which will no doubt make.
I would pass in this spot at MP. My partner won't pass this out without spades!
I wouldn't bid 1N, because the most likely action is partner transfers to 2H as a drop, and I'd way prefer to defend.
I don't bid 2D with this hand. Since your problem forces me to, I am kind of screwed. Passing 2H is gross; P thinks I have a 10 count and will be reluctant to compete. If he does compete, I have no idea whether to raise, so I kind of force myself into a X at this call to show a good hand. But then I have no idea whether to correct 3C to 3D. Blech. I'll pass if rho bids 2H, but this is why I didn't bid 2D last time. What happens if I pass initially?