Answers:
1.
Hint: How will partner take your call? Will you be okay with his reaction to that?
Answer: You have opening values but no call describes your hand, and if partner has an average hand, you are unlikely to make a contract above 3H.
The worst error is double, which is for takeout. Partner will almost certainly bid some number of diamonds depending on his strength, and you will be in big trouble.
Overcalling the four-card club suit isn't much better. It bypasses your most likely game (albeit one you can't realistically reach) and suggests that it's okay to play with clubs as trump opposite a doubleton (when you start talking at the four level, your bids are more serious about suit quality.)
While 3NT (a call that I don't have the values for) is the call I would make if I wasn't allowed to pass, it gives up a great opportunity. Partner is short in hearts and with close to opening values, is likely to reopen with a takeout double, which you will pass and collect a fortune.
If partner doesn't have enough to reopen, you collect 50 per undertrick with the knowledge that you were unlikely to make anything.
2.
Hint: How will partner interpret your call? Are you happy scoring 50 points a trick here?
Here if partner has seven points or so, you want to be in game and partner won't do anything. The most likely game for you to make is 3NT and that is the recommended bid.
Admittedly, the transportation will be difficult in 3NT, but it appears that the opponents will have to help your side when they get in. Partner has 0-1 hearts and his length in the other suits will usually prevent the opponents from getting five tricks.
3.
Hint: If partner has a good hand, how will he react to your call?
Answer: Only one side gets to preempt on a hand. A 4D overcall shows a decent hand, and a 5D overcall shows a better hand; one that thinks it will make 5D opposite an average hand for partner that wouldn't bid over 4D.
If you bid any number of diamonds, partner with a decent hand will think you have the values for that bid and drive to an unmakeable slam.
You should pass. If partner gets active, you can insist on diamonds later.
4.
Hint: If partner has a moderately bad hand, how will he react to your call?
This is what a 5D bid looks like.
You're likely to make 5D opposite a weak (but not bust) hand where partner would pass 4D. You should guess that partner has a smattering of values and bid based on that. If partner has absolutely nothing, the preempt has done its job - but unless two diamonds cash on defense, 5D might be a good save against 4H in that case (although that is not a consideration when I choose to overcall 5D.)
I don't like 3NT because partner isn't likely to run and West will happily defend with a heart fit.
Double and correct to diamonds has an issue when partner passes the double, or if partner insists on making a long weak spade suit trump expecting support. Bidding 5D emphasizes diamonds as trump and this hand calls for that.