I can't answer the questions about RN work, but if you're feeling like you're playing catch-up on the chores on your days off, I think it's time to enlist the rest of the family with that. Yes, 6 and 7 year olds can do everything, but they can be taught how to load a dishwasher or wash dishes by hand. They can sort laundry and do basic laundry if they have a stepstool/assistance in getting it out of the washer. They can learn to sweep the floor, wipe out the bathroom sink, swish the toilet bowl w/ cleaner, etc.
I would say that you should sit down as a family and discuss the issue (maybe discuss w/ your DH first, so he knows what's coming and can help with the conversation). Explain that you miss the kids and want to spend more time with them. Explain that in order to be able to do that, everyone needs to chip in more so that Mom isn't spending all her time at home cleaning, and instead spend more time doing fun stuff. Then, enlist their help (maybe make a chore chart to help with it). Dad will need to be on board, since he'll be supervisor for the kids when they are doing their chores....
Maybe, on one night per week, you can let the kids have a special, late bed time of 9 or 9:30, so you can come home and play a game with them or read books or watch part of a movie. Try planning other things, like, have Dad bring the kids and meet you half home to go putt-putt golfing or bowling or something like that once a month.
My SIL struggles with this... her kids were a little older when she started, and she did switch to the night shift. However, the kids bedtimes, especially the younger one's, got totally messed up. He'd stay up really late just so he could see his mom, and then be tired all the time....