if I send lisk to an address that has already voted, do I have to "vote again" to reweight my votes to the higher amount?
Your vote-weight is dynamic and applied at the end of every round.
If whale-X voted in delegate-Y with his weight being the determining factor, the moment the lisk transfer out of the account, the voteweight is gone, then applied accordingly at the end of the round of 101 blocks, and Delegate Y would drop rank.
Same thing if you get more lisk in the account, if it's enough, it will push ranks up; no re-voting necessary

When gembitz trolls, it usually means :
■ the charts looks interesting, trading-wise
■ the $lsk and #lisk twitter activity will increase in the following days weeks
■ the quantity of trolls here will increase a lot
■ the price will start to increase and probably pump (depending on what btc will do though)
Coming days and weeks will be funny here.
brb.... making some pop corn. ttyl
hehe somehow I knew the natives were getting nervous