I'm playing testing at the minute, not sure it it helps but will keep on eye on the issues you mentioned above and post some feedback here. From what i've seen so far though, I would agree that AI seems to leave a lot of goodie huts and quest locations behind... but I can't really comment on if thats changed in 1.7 because I haven't played beyond early game for a while.
In LH 1.6 and previous versions, the AI players used to clean up their territories of weak and medium quests. They'd do strong ones occasionally and deadly ones very rarely. They pretty much don't bother anymore, probably too busy getting their heads handed to them by those adjacent monster lairs. Now it's worth sending a solo champion to reap your neighbors untouched quests, get their Panca Archers and Ophidians and skyrocket your fame score to Elemental's moon. As for the untouched goodie huts, monsters now tend to leave their lairs, roam around and strange things can happen to them (ie getting killed by the Denizens of the Wildlands for example).
Hmm. I enjoy how the AI takes fewer quests and goodhie huts. On Expert/ridiculous, they always seemed to take them all before I could!
Yes, it hurts them, but I'm not sure it's a huge difference.
It was indeed a race to get to those quests but I'd say it was fun to prioritize triggering them before the AI could. I will confess that, once or twice, I had scouts stand on quest huts to prevent anyone from getting to them before me.