SOLUTIONS
1. Pass: 2S on a five card suit is out. 3D showing opening bid values is also out. What's left is the best bid in bridge, PASS!
2. 3H: You have enough to invite. That HQ is a big card.
3. Pass: 11 HCP is enough to bid 2NT, but the singleton heart reduces the value of your hand a point or two. This could be wrong, but more often than not you will be right.
4. 4D: A slam try splinter showing a singleton diamond, three card heart support, and slam invitational values. Perfect.
5. 3S: Invitational. With one more spade and one less club, you should jump to 4S.
6. Pass: Don't look for trouble with a likely misfit. There's always the next hand.