I would very much like to laugh at/read the game where you got spiked with a lead-filled coin.
I like 1 and 3 (mostly because raising their level also devalues how much the si can be sold for, along with raising prices in shops, not worth it for me, I let them build then sac them all away at once), the levels they receive are supposed to ward off stealing them back (god forbid they try to enact revenge on you) and I personally think that 28+ levels is a great ward against it, considering you got hit with a 800 damage coin.
This has my vote.