The average reward will even out over the long run, but that also means you will need to stick to that one pool over an extended period in order to reap the expected reward.
That's wrong. You could mine in a different score-based fair pool every day, and your total rewards will still converge to the average.
That still defeats the point by restricting the miner to a small number of pools, which would have to be similar in nature, at least for the fee system. Good luck with that.
zero-fee PPS
There ain't no such thing as a free lunch. PPS needs to take a fee to maintain stability; and, conversely, PPS has a lot of advantages so it is reasonable to pay a fee for it. I think going forward we'll have stable 1%-2% fee PPS pools.
zero-fee PPS pools do exist. Whether they are sustainable over the long run is another matter altogether and quite beyond the scope pf this discussion. Whether fees are reasonable or not can only be decided by the open market system. Users will not accept fees if they do not perceive getting adequate value for that fee (as long as there is a lower fee alternative available).
proportionate pools do not have the intermittent issue
That's wrong. Even setting aside the hopping issue, proportional pools have higher variance than a PPLNS pool with the default parameters. So if PPLNS is bad for intermittent miners, so is proportional.
I have already mentioned that proportional pools have higher variance than others, in the second line of the very paragraph you are talking about.