I feel your pain. :-) But as for the first question, I would say no. For example, it happens sometimes that strong mathematicians decide to post to MO for the first time, and your suggestion would not be a reasonable hoop to make them jump through. I'm not sure what mechanism you have in mind for the second question, but off hand I am skeptical.
I haven't tried to analyze the number of questions which seem to fall short of current MO standards of being on-topic. As a moderator responding to flags, I spend a disproportionate amount of my time on questions that arguably fall short of those standards, and yet my overall feeling is that most questions we're seeing these days are fine. I would welcome a more careful analysis however.
Your second paragraph raises a good point. There are questions that are in a kind of limbo of being easily answered but which no one feels moved to banish through a closure; my guess is that people who answer in comments might feel diffident both honoring an easy question (for them) and reaping points by picking low-hanging fruit by posting an answer. I know I sometimes feel that way.
A kind of stop-gap measure is to offer up a CW answer (and I do feel that is both appropriate and in good taste, for people who want to post an answer based on the ideas of others in comments). But in the end I agree that it is probably better to have the courage of one's convictions: if a question doesn't belong, say or do something to that effect, or if it does and you can give a strong answer, then do so in an actual answer box (in other words, don't be shy). I think many regular users do operate by that ethos already (in other words, I'm not sure we have a serious problem here). Meanwhile, as we encourage others to adopt that ethos, the CW option might not be bad for people who wish to whittle away at the unanswered queue. As always, I welcome comments on this idea.
Edit: Referring to the last paragraph, it would be in even better taste to ask a commenter if he/she would like to make their comment an answer, and create such an answer only if they reject the request or do not respond. I'm sorry not to have said this earlier.