4th suit forcing gone wrong

I held a really nice hand, especially given partner's 1C opener.
8
A1052
A104
AKJ87

The auction proceeds:
1C - 1H
1S - 2D (4th suit forcing)
2H - 3C (now, I've set clubs. Partner may think hearts is trumps, though.)
3H - 4D
4S - 6C

I decided that 6C should at least have some play. Partner may have thought hearts were trumps all along, and by leaping in clubs, that should remove the ambiguity as well.

Partner's hand was
AQ52
KQJ
Q63
1062

Q1. You be the judge. What was the worst bid? Who was more at fault?
Q2. What percentage of the time will you make 6C? Opening lead was the heart 9.
Q3. Would you rather be in 6H?

After this auction, we have now tweaked our agreements in two ways. First, we have agreed to rebid 1NT instead of 1S when we are specifically 4=3=3=3 shape. (and we've augmented our 2-way NMF auctions accordingly.) Second, we have agreed that responder's third call suggests the trump suit, rather than being a cue bid.


4th suit forcing gone wrong