Discouraging frivolous close voting by adding a small cost like downvotes on answers

Not in my experience. You seem to be wanting to impose your view of when a question should be closed on everyone else. My bar for a good question tends to be higher than the average, but I strongly resent your attempt to punish me for that. Let the voters decide.

You are basically saying that if I see a question that I think is bad, then I have to consider what everyone else might think before casting my vote on whether it is bad. That’s just plain wrong. It will lead to fewer questions being closed, which is apparently your real objective. That will not be good for the site.

How about the flip of this? Punish those that answer a question that was later deemed bad?

And also add some punishment for those that attempt to circumvent the will of the site by posting an “answer” as a comment. This is rampant on SE. There would be an “Answer in comment” flag. If enough (3 maybe) such flags are cast, then the comment is deleted and the commenter looses something.