This is a good approach. I think the calls for long term payouts would greatly subside with an effective tipping system.
A blockchain feature that makes sense for tipping is a change purse (with a user-defined max balance) that can be used to receive and send tips with only the posting key. Or alternately some sort of rate-limited tipping ability from the regular balance with posting key.
Perhaps with an automated aspect: if the payout is already made, you can assign a certain amount to be tipped by your simple upvote.