Another thing I did was replace my natural gas water heater with a hybrid water heater (has a built-in heat pump to use when running in efficiency mode, and normal heat strips when running in normal mode like if we have extended family over). I wouldn't get it, though, if you have a large family still living at home. (With just my wife and me, our 50 gal water tank has enough hot water for the two of us to take a shower, but after that it takes 2 hours in the summer to 5 hours in the winter to reheat the tank in efficiency mode. That wouldn't be good enough when we were raising kids.) In efficiency mode it runs at 300W instead of 4kW like a standard water heater (or 12kW like an inline one). Plus, it runs shorter in the warm months because its intake draws warm air from the attic (thanks to a duct). And it helps cool the house because it outputs free cold air (which I pull in with a HVAC air intake installed in the floor of the closet the water heater is in). During the winter I flip two levers and the water heater's cold air output is ducted to the attic. During the warm 7-8 months I use the free cold air to help cool the house. Because I have a variable speed heat pump and air handler, my HVAC is almost always running even if it's in low mode. (In other words, any time of day the water heater runs, the cold air will be sucked in by the air handler.) This keeps my variable speed heat pump from having to operate on higher speed while the air it draws in is a little bit cooler than normal (because some of the air came from the water heater).
Sounds like you have a good plan going on. I live by myself and my hot water use is relatively miniscule. My killer is the a/c. When it’s 99 during the day and 82 at night that’s bad. I’m hoping when, and if, temps get back to normal I’ll see the results of the attic ventilation improvements. I’ve asked my a/c guy several times if I need to get a new a/c and basically he said your a/c if fine, it’s doing everything it can do, and replacing it would not be worth it at this point. I just put a new $900 blower motor in it so hopefully it will last a while.