Tough problems.

PROBLEM A: Double
PROBLEM B: Double
PROBLEM C: 1 Heart. I like my hand.
PROBLEM D: 1 Spade. I want to play at the 2 level. I don't want to hear an invitational bid from partner after 2H.
PROBLEM E: 3 Hearts
PROBLEM F: 3 Notrump
PROBLEM G: Pass. We probably have a minor fit, but I don't like risking going down in MP.
PROBLEM H: Club 3. No rush to cash side winners, they won't disappear after the trump lead. It's unlikely partner can get in. I'm worried about being thrown in.

A. 3S. For me this is a matter of 2S or 3S fit bids. Since partner made a WJO, spades bid must be fit showing bid. Although the S length doesn't seem to be sufficient, but it should be just lead directing. I choose 3S, jumping to the level I want to be at.

B. 3NT. Double fit. slam is possible vs. a medium strength partner.

C. 2C. Partner bid my singleton and we doesn't seem to have a S fit, so I will just bid 2C and wait. If partner rebids 2D or 2NT, I'd bid 3NT.

D. 2C.

E. 1NT. To me that's a 4 card S suit.

F. 4NT. Pick a minor.

G. B6. I don't really like this option, I feel it screams for a club lead. But I like to show my solid D this way and hope for luck.

H. H6

It takes some courage to post my answers and share my thoughts here. I know pretty good players are around here.

Problem A: 3C. It shows my shape and strength.

Problem B: I see a few options: 3D. this hand is too strong to bid 3D.
                                              3NT. It should show a long D suit with 16-19 hcp, the other suits stopped. But here, I feel the D suit is neither long enough (maybe one more D) nor solid enough(maybe one more J at least).
                                              2NT.  I don't really like. With all very good controls and a small singleton, I don't feel like showing a balanced hand.
                                              1S. The problem with 1S is it's not forcing. But if partner can't make a rebid over 1S, we probably don't have anything anyway, because for me rebid 1S after 1D always shows a shapely hand, usually 5/4 in D/S (could be 4441), so even though with a very minimum response, my partner would probably make a 2D rebid with 3 cards. If he doesn't even have that, we probably don't have anything anyway. And 1S is flexible, with any of my partner's rebid, I can show my D again. But again the problem is 1S doesn't show my strength and probably hard to show such a good hand later after partner's rebid.                                                   
                                              2S.  It is a jump reverse, also lying about S suit, but I feel the lie can be expected more than 1S. I tend to make a lying jump reverse in this situation. And more importantly, it shows my strength. I go with this bid.

Probelm C: a3. I'm reluctant to make a reverse here, but life isn't perfect.

Problem D: 2C. I feel this is the only option if choose to make a bid.

Problem E: 2H. I don't want to pass risking partner having 3 cards D and I feel with 9 hcp I owe my partner a bid here.

Problem F: Pass. This one is a real headache for me. I decide to make a bold bid. Partner has Hearts for sure. My second option is 1NT.

Problem G: 3C. I don't see other options.

Problem H: S4. I tend to make a passive lead against 6NT.