Pass or Pull Revisited

In what has become a recurring theme, here's another controversial hand!

2nd seat none vul you hold
Jx
xxxxx
KTxx
Ax
After two passes, the action starts. LHO opens 1 Club, partner overcalls 4 Spades and RHO bids 5 Clubs. This is passed back to your partner who reopens with a double. What range of hands does he have? More importantly, what do you call now?

Is There a Middle Ground?

I held this hand, vul vs not as dealer at rubber bridge tonight:
void
763
AJxxx
QT9xx
After 2 passes my partner opened 1 Heart, RHO overcalled 3 Spades and I didn't think too long before bidding 4 Hearts. My partner played it well and made and we continued playing but for some reason the hand struck me as interesting. Say you held this hand and partner opened 1 Heart, passed to you. What's your approach? What about if RHO overcalls only 1 Spade? What if you make one of your minor suit spot cards another small trump--how does that change things?

Another 6-Level (Mis) Adventure

I just finished playing a full weekend of bridge--so much for one of our last beautiful weekends of summer weather here in Chicago! Here's my favorite hand from today's Swiss, once again more for the humorous side of it than the result (as you will see).
I held 2nd seat favorable:
AJTxx
Ax
AKxxx
9
I opened 1 Spade of course and our unobstructed 2/1 auction continued:
2C-2D-2NT-3D-3S-3NT-4NT-?
I could hardly have a better hand so I was for sure driving to slam...I still didn't know where to play though. How good were partner's spades? And could diamonds still be in the picture? I bid 5NT, accepting the slam push and asking partner to choose. He bid 6 Clubs, which i wasn't expecting... Now, though, I started to envision him with something like AKQJx of clubs and Kxx of hearts...if the opponents didn't lead trump, maybe the heart ruff could be a vital extra trick! Sick, I know, but I passed. Alas we went down because of a 6-1 trump break. And 6 Spades or 6NT would have made. At least it's a story--it isn't often that you voluntarily play a 6 card fit at the slam level. Partner's hand:
Kx
KQxx
xx
AKQxx