Is bidding nil while holding the Queen of spade reasonable?
Your proposed hand is an excellent hand to bid nil.  Because literally the only issue is with the Q♠ I'd try for it whenever partner bids does not also bid nil and your team doesn't have a huge lead or is about to win the game.

Remember that your opponents have no particular idea of where the weaknesses in your nil hand are, so they won't necessarily be able to set you up for failure without possibly missing their own bid.  Realistically, the only risk you face is your Left-Hand Opponent holding both overcards.  Then they could play the A♠ and K♠ if you don't use your Q♠.  But that's an unlikely distribution (1/9 chance), especially if your partner bids high.  

As for bidding nil with the Q♠ in general, it's certainly worse than a side suit queen, but high bids from your partner will mitigate this weakness.  You need a more perfect suit holding since you can't protect the Q♠ with length because it's the trump suit.  But I don't think that single card makes it too risky to avoid bidding nil outright.