I fear the massive levels of abuse it could bring -- the possibility that someone would commit suicide because their organs can take care of their family and they can't, that someone's organs could be used as collateral in a loan à la Merchant of Venice, and of course, the temptation to gain the organs of others by force..

Only the last is an abuse. The preceding points were merely uses that you're uncomfortable with.

I wish people would get this straight. Just because you're uncomfortable or disapproving of a particular utilization of a right or ability doesn't constitute an abuse of that right or ability.