Yes, but it is wrong to do it, unfortunately, just about everybody does it... :-(
Actually, I don't. That is a cheap and unfair thing to do, and a pox on all those who do.
That is why I said "Just about", I know some people who don't vote for their own ible.
Not as yourself. Admins do look for funny-voting patterns, if you were to create multiple accounts to rig-voting on yours it may well be disqualified.
You could, but your vote would be disallowed.