Chess Ethics Question: Offer to Draw

In a game, I was behind two pawns. I was able to perpetually attack to recover one. Best play for opponent was to take the draw or repeat the same defensive moves three times and draw. Because otherwise, ending the repetition the king would have to move into a mate trap.

I believe that if you offer a draw, and the opponent rejects the draw, they're biased for a while to go for a win. After all, declining a draw just to walk into a draw within four moves is like admitting you made a (social?) mistake by declining the draw earlier. People don't want to be seen as forcing pointless moves.

So here's my ethics question: I figured that, if I offered a draw now, she would decline because of material advantage. Five moves out, running from the draw by repetition, she might abandon the pawn to avoid the (shame) of having a draw after so recently declining.

Of course, I pre-programmed my conditional moves, making our daily 14 day per move game shorten to instant moves. She could have taken the full 14 days between moves, but, why not move now?

So she moved her king down, right into my trap, and it was mate faster than you can say, "add cheese, please."

Was it:

1. Unethical to offer the draw, while hoping she would blunder into my ambush?

2. Was it unethical to pre-program my "conditional moves" to reduce the time she might spend to look for traps?

I know it's within the rules, I'm talking about morality.

3. Is chess an immoral game, we're constantly hoping the other player is ignorant?

No, it's not unethical to offer a draw, especially in the circumstance you saw. It also wasn't unethical to use conditional moves to handle the situation.