I like what you've committed to github. Back on target for 2 minute blocks and 4 block retargets. That with the 4 block lookback for retargeting should help with getting difficulty stuck.
This. I wish there was a way to actually target difficulty based on profitability rather than simple hash load. It would certainly help with price adjustment following the reward drop. At that point people who are mining it heavily will likely already be large holders.