Should Questions be Limited?

Yes, they should be limited to being actual questions.

Hey Dear, Am Sasha a nice young lady, your profile is nice,am interested to know and share ideas with you only if you don't mind. I will be waiting for your reply at (sashaghanemlove (AT) yahoo.com) because i don't visit here often, when you write i have something very important to discuss with you, thanks.
Sasha.

I have not seen any sort of abuse done by anyone to justify any limitations. The few people that post a vast amount of questions, tend to ask really good thought provoking things so I wouldn't suggest limiting them at all.

Yes, they should be limited to being actual questions. So many are blatant attempts at sharing a link in the hope of attracting a click (a visitor? or even a sale?). Some limiting factor, such 3-5 questions asked each day (or until a fixed number of questions asked by others) would also help to prevent the "flood" of questions.

I think it should be based upon the response rate.

Thanks Warren, agree. Questions look more like some sites' dashboards

I think some kind of flood control should be in place and my preference would be no more than 3 questions asked until 3 other people have had a chance to post theirs, or the next day whichever comes first.