1.) A solution in which market activity reflected a cross all exchanges is not inhibited
- Lenders seem to have a hard time with this one, the market will swing 10-15% if part of your funds are lost on a very natural market movement that is your responsibility as a lender, and you must own it. BFX kindly offers insurance which is an offer I think you would have to be crazy not to take.
The problem is that the total insurance funds are only ~55.000 USD. I think many lenders would gladly insure their loans, but simply can't because those 55.000 USD are always taken. If every lender would only offer swaps if they are insured, all traders would have to fight over only 55.000 USD liquidity offers with probably astronomically high rates! So i think it's a bit short-sighted that a few traders (not you!) think that every uninsured lender should lose all his money because of a technical/organisational issue (e.g. price crashes to 1$ because BFX doesn't have enough coins/USD on bitstamp or whatever) so that some traders can make profit, because "it's the lender's fault if they don't take insurance".
But as someone who lends some of his money, I don't think that it should never be possible for lenders to lose money! As you said, if the market swings 10-15% (or more) on a
natural market movement and i lose money, then i can hardly complain.