Perhaps the function should be split into two user-interface items?
Allow downvoting to remove funding; and have flagging which makes it invisible?
I'm fairly new here (a month or so), and know that I need to read the whitepaper for better understanding, but it seems that a simple split would resolve your quandary.
As far as the money aspect, that's what I need to know more for -- i.e., should the flagging cost the same as the downvoting? My initial guess is it should cost more, as blocking something is a stronger action. Cheers!