If time went back, would Syrians want to start a revolution now that they know what will happen?

They likely couldn't say at this point, since it hasn't concluded yet. However, if Assad is eventually removed one way or the other, I would imagine they'd definitely feel it was worth it. And at the least, it has brought Assad's atrocious deeds to the global spotlight.

However, most of them that aren't fighting still are being killed off by Assad out of revenge anyway, and their families with them.

In the end, no one can blame them for fighting back, regardless of the outcome. . .well, no one but Assad and Russia, that is.