No. Not voting CAN absolutely be voting "no."
It's just not the answer to the exact same question.
Given two (and only two) "choices" worthy of the name, refusing to vote at all is the same as voting "no" to the entire (false) choice.
Okay. It just won't decide the election. The election will be decided only by those who vote.
That, too, is not entirely clear. If Romney needed just two more votes to win the Electoral votes of my home state (I live in NY, so the example is of course purely hypothetical), but I decide not to vote, he loses the vote he would need from me to have it decided as tie. The one other person who would have voted for him if he had voted at all but who instead decides NOT to vote thus decides the election in favor of the person he would prefer to lose.
It may come with consequences, but a refusal to vote can count as much as the vote that is cast.
All you are saying is that elections will be decided by those who vote. Not the votes someone would have cast if only they had voted. If there is an election and 90% of the people vote, then the election would be decided by a majority of voters. If there is a 2% turnout, the election will be decided by the 2% that show up. It doesn't matter how many don't vote. Elections are decided by those who vote.
If what you say is true, then you had decided to vote for Romney, but for some reason decided not to vote and he loses the vote he needed to win. All that means is that your voice was not heard. You have disenfranchised yourself.
You remind me of a woman who wrote a very bitter letter to the editor in the local paper. She voted in a mayoral election and her candidate lost. She was very angry because her vote didn't count. She felt disenfranchised. Her vote was stolen from her because her choice lost. It was all for nothing. This is what elections are all about. You vote. Sometimes you win, sometimes you lose. Those who don't vote will never be able to elect any candidate. They might feel they punished a candidate, but they haven't really. Not any more than if they were on their way to the voting booth and suddenly dropped dead.