I agree with you in most of what you say, being my own preference to now mine on a DGM pool, whether better or worse, is a choice i've recently taken. With regards to the finders bonus, well, for me it is irrelevant really, for the specific reasons you state above; with only 170GH/s I am too small and will never be a block finder under current and future difficulty - except for some freakish luck, which I doubt will ever occur. But isn't it the case, as BTC price rises, tx fees need to be smaller - nobody wants to be paying an exponential fee to send bitcoins. this would in the end make it cheaper to use a credit card for purchases, which goes against the purpose intended for bitcoin in the first instance?
I'll remain with my thinking that giving the block finder a bonus is a good thing, even though I will never see that bonus personally, I think it gives extra incentive to mine.
I agree about tx fees having to be smaller. The hope is the volume of tx fees increases to keep the incentive there for miners. Of course what could happen is as the block rewards continues to halve, if transaction volume doesn't increase, the incentive to mine decreases, which should lead to a decrease in difficulty. But, as Gavin says, we don't know what's going to happen. It's an experiment.
M