EDIT: Oh, and of course, there must be tolerance levels too (if I'm X blocks behind the chain I once rejected, I'll give up and start building on top of it). You don't want to create that many chain forks! 
Absolutely. Of course, that sadly means that we won't be able to ever trust a block until it gets past that point (which I think should be 2-4 blocks).Would it really? I've never seen any actual analysis, but I'd say that honest splits would mostly carry the same transactions, with the obvious exception of coinbase and "a few others". Has anyone ever done an analysis of how many transactions (in relative terms) are actually lost in a reorg and need to get reconfirmed?
Btw, interested nodes could attempt to download, and perhaps even relay, all sides of a split. If you see that your transaction is in all of them, you know it actually had its first confirmation for good. Relaying orphans sounds a less radical change than changing the 10m delay...