I agree with the "money bag" idea. It would be good for those who wish to keep their pirates sort of a secret. Assuming of course that neither Wolfpack nor Igiss will spoil it.
As for losing a percentage of your money, NO WAY. I don't want to lose money for PvP. I like to fight people for fun, and a lot of that(for me anyway) is dying. I'm not even in favor of losing NB/SB and ammo, why that? I reapeat myself, NO WAY!