As I said, your answers to Q1, Q2, Q3 are correct and your proposed strategy works for that case. But there is a nice proof (besides trying it practically) for that in all cases, not just the one you mentioned (which may or may not be what player 1 choses to play).
I'm adding a question to the OP, about a slightly modified version of the game, which hopefully might provide a hint on why the strategy works in all cases.
Question 4) For what M and N does the second player always have a winning strategy, if the figure that needs to be covered is selected by the first player?