I go to theme parks around the world for a living. It's absolutely worth it to go to Tokyo DisneySea. Probably Disneyland also, but if you have to prioritize, head to sea! Everyone has answered your questions very well and very correct, I'll actually be at the parks next week and can answer more if needed. They are being run VERY differently now than pre-Covid so as much as I hope by your visit they will be back to normal, this may be a 'new normal' for the parks.