Just wanted to check back in and update. It appears to be a lot related to Strangerville, which I had just recently installed-really should have checked the forums first. The game I was playing had included my run through the Strangerville story, which appeared to have an effect on all neighborhoods. As long as I stayed in that game, the significant lag continued.
Looked into uninstalling just Strangerville, but I am woefully low tech and not confident. So I just deleted my game and all prior ones, cleared all caches and generally tidied up, then started a new game without touching Strangerville. So far things are much better, without the 2 hour lag with cooking and eating. I'm still seeing extra long showers, but my Sim hasn't gotten her plumbing fully upgraded yet. Still the occasional standing in front of the fridge to eat, but will follow instruction to go sit down, and will spontaneously do that about 75% of the time.
My prime suspect is Strangerville as the root cause of the issues in my game. Have tentatively ventured into knitting again, and as long as I keep the basket out of my Sims inventory when she's not knitting, we're good. Phew.
