Hi, Liz. I don't have much input on the new blended-family and Dad issues. Just wanted to let you know you're not alone: I worry that I've let DS slide on a lot of things trying to make up for the stuff we've had to deal with regarding his Dad and I'm trying to stop/change. It's tough, though. I find I still tend to want to step back if DS doesn't like the changes and I have to push myself to keep on. (In all honesty, though, I kind of think it has a lot to do with my perfectionist traits: I can do *this* faster, easier and with better results... so it's not just the alcoholic-dad stuff.)
DS has a hard time remembering what's on the chore list, even though it really doesn't change much day-to-day. We ended up writing out a brief 'schedule' for him and put it up on a chalkboard decal by the fridge. (First stop when getting home is always looking for a snack.) It's working out pretty well. He feels more like he has some control because I didn't TELL him to do it and I feel less like a nagging mom. I know your son is older than DS, but maybe there's some other method that would help him? (I've been using a combination of a weekly planner-bullet journal to help me keep track of what I need to do.)
((((hugs))))