I personally love Epcot and think you should give it a try. I find I can do a half day at both HS and AK,but can do a full day at least at both MK and Epcot.
What is it you love about Epcot? We ran out of time at both HS and AK so I wonder if its because it was all new or if its because the things that we are interested in are not the things that people like about Epcot. That's not coming out right but hopefully you know what I mean
to be honest i'm not sure why you are even considering skipping epcot.
sounds like epcot is right up your alley!
there are SOME rides but also plenty of non ride activities/enterntainment.
there's interactive areas after most attractions like after journey into imagination with figment, the seas with nemo and friends, mission space, test track, and spaceship earth.
there's also innoventions (only east at the moment).
captain eo is coming back this month.
the countries in the world showcase offer tons of entertainment such as short cultural/historical films, singers, dancers, and interactive storytelling (i love participating in the shakespeare play skits in the UK)
there's also plenty of characters to meet in both future world and the world showcase.
and in my opinion illuminations reflections of earth is the best nighttime show disney world has.
universal doesn't really sound like your style.
its mostly rides/simulators and not many character interactions.
if you really enjoyed discovery cove that much then i'd be trying to decide between that and epcot not that and universal.
Honestly after reading this thread I'm wonder why I'd skip it too!! It is starting to sound more and more like things we'd like.
and just putting it out there that epcot has a dolphin interecation.
although you must be 13+ so this may not work for your family if your 10yr old wants to do it.
https://disneyworld.disney.go.com/events-tours/epcot/dolphins-in-depth/
I did see that but I would never book it if it meant only one of my kids could do it and Discovery Cove was so much more than dolphins - it was the whole day experience I loved.
I can't imagine ever skipping Epcot on one of our trips! We even stay at the Epcot area hotels in order to be close enough to walk there for dinner!

Oh we're staying at Caribbean Beach Resort - can you walk to Epcot from there?? That would be even more incentive for us to go on arrival day.
I think of Epcot as a lot to see, but not a lot to do. I like it, but to me it's the most exhausting day. Everything feels very spread out with very little shade for your walking, and it's a lot of walking/looking. WS is beautiful and amazing to see, but it's really just food and shops with a few shows mixed in if you plan well enough to catch them. When my brother and I were your daughters' ages, it was the park we skipped or did for a half day. We appreciated it more when we were a little bit older. You should definitely see it at least once.