Electoral college and FPTP need binning. You get some sort of ranked choice voting, better access to voting overall you'd have a lot clearer picture of what people ACTUALLY want. They also should really be expanding the number of the House as that was meant to be the voice of the common folk. For some reason there was a cap put on it in early 1900s that meant no matter how large the largest state was they would only be a set number of Representatives in the House.
Electoral college is based on House/Senate seats which is why the electoral college is also a mess - no change in House seats as you said.
Small/low population states will lose a lot (from their perspective) if you alter electoral college and House...although I think both changes are warranted.
Likely need to start with one or the other to even have a chance.
I'd fix gerrymandering in states (state and federal level) so there are more competitive House races first. Nothing is getting done in the legislature in part because those being elected are on the extremes and are unwilling to compromise because they don't have to...they are more likely to not get reelected for compromising with the opposition.