100% pass. "Not even think" pass. If you're worried about "what happens if", this is the hand to worry about it. No, you're not likely to go 800, but you are likely to go minus on a "nobody can make anything" hand. At rubber, that will cost you tiny bits that will add up over the year. At matchpoints, -50 when you could have been +100 is almost as big a loss as -50 when you could have been +400.

All my arguments from the previous hands apply here:

• ⋄Qxx is not only wasted values, it's valuable on defence.
• If they have a fit, partner will do something ("short hand acts"), and you will be happy to support whatever she does. If they don't have a fit, you're losing 3 diamond tricks, either straight up or A,K,ruff.
• It's now screamingly clear that this week's course is "if you double 'because I have 13 points', stop."
• specifically on this 14, look at which finesses are (potentially) on. To me, it looks like just the ♠J. That means any card LHO has is working to pick off your cards. On defence, the KQx is likely two tricks. On offence it could not be, if that's their fit and partner is short.

All of Forget...'s arguments on other of your questions also apply, in spades:

• downvalue 4333s.
• downvalue aceless hands. They're better on defence anyway.
• you have a partner.

If it goes 1⋄-p-p to partner, she will likely have the hand that knows what to do. If it goes 1⋄-p-2⋄ (whether the opponents play that as "single raise" or as "limit or better"/"GF"), partner definitely will know what to do (at least if she adheres to "short hand acts" at all). If it goes 1⋄-p-1NT, this might be fun.

Alternatively, if it goes 1⋄-X-2NT/3⋄ (whichever is limit raise), partner has nothing and declarer can see the entire hand (although he might play for partner to be ⋄Qxx). Same for 1⋄-X-1♥-p; 2♥-p-4♥, with the benefit that trumps split better than they hoped. Sure, if you pass, the same auction happens, but now maybe there's a misguess.

On the off chance that it goes 1⋄-X-XX, pull out your wallet. I know, paranoid, but again, if it happens, the opponents know exactly what to do.

I'm more aggressive than Joe; with perfect shape, I'll double on a good 10 or less with no wasted values. My partners know to double-check with a good hand. I'll balance with even less and perfect shape, especially into 1m-1M; 2M-p. But flat hands are a danger when they've opened, no matter how many eyes are looking at you.

Now, with my regular partner, I will act with this hand. Because I'm playing something weird. But:

• I will make the same call with Kxxx QTxx x QJxx, or weaker at favourable. The wide-ranging, aggressive nature of the call provides some safety.
• I won't make the same call with most 15s, so partner won't go nuts.
• That call is 1NT, not double, which takes away the 1♥ and 1♠ responses.
• We are very prepared for the penalty "redouble" (actually double), and our rescue system is built to expect it. We are much more likely to reach a fit than the regular takeout doublers (albeit at the 2 level).
• I will take 100% of the blame if, even so, it was wrong to act. And it will be, sometime, sure as apples is apples.