QUESTION: Would Declarer make the contract if a small  Diamond was lost before Hearts were played?

Not with good defense. The Defender who won the  Diamond trick has to lead a Heart. 
       But why not lead a Club? That lead would be more dangerous than the Heart lead because the A C or the KC of Clubs is being "underled". Banging down the Ace or the King is equally bad. The safer exit card is a Heart by any Defender. Now Declarer is forced to play Clubs and lose 3 tricks in that suit for a one trick set. 

1. What deceptive play can West make to set the contract? 
2. Is 3 No Trump a better contract?

1. Refuse to win the Q  the first time the Club Finesse is taken. A tough play. Because if the K C and A C are now played the Q C falls (so does your partner's mouth) and the Declarer makes an over trick. 
      But what Declarer will not take the Finesse the second time? (A Declarer with X-ray vision or good ESP). For it is very possible that East has 4 Clubs to the Queen and the Finesse has to be taken twice to pick up the Queen.
       Here's what happens when East refuses to win the Q C the first time the Finesse is taken. The Finesse is taken again and now East wins. (Try not to gloat too much; bad Bridge manners.) East returns a Spade which wins in Dummy. But the Club suit blocks; it can not be run. The next Club trick is won with A C in the hand.  But alas, there is no way now to get to Dummy to cash the good Club. The Declarer will now lose 3 Diamond tricks; and this plus the Club loser sets the contract.

2. Good or bad is sort of relative in Bridge. And it is not always possible to analyze a Bridge hand solely by results. In this particular hand 3 No Trump does easily make with over tricks. Count winners. 2 Spades; 5 Hearts; and 2 Clubs for 9 tricks off the top. The two over tricks will come in Clubs even if the Finesse for the Queen loses. 
     But let us change this hand a bit. Give East/West the A S and North/South the Q D and J D. The bidding is the same, but 3 No Trump will not make.

TIP: With a fit in a Major suit it is usually best to play in a suit contract. Two exceptions:
       1. The hands are very flat. No doubletons, singletons or voids.
       2. The hands are fairly flat and the combined point count between the two hands is over 30.