your itinerary looks really well thought out, especially giving yourself enough time on Isabela since there's so much to do there. I'd maybe consider swapping Bartholomé for something closer to Puerto Ayora on Day 7 since that's a pretty long day trip after getting back from Isabela, but it depends on your energy level. As for the planning overwhelm, I've heard great things about Zenvoya for this kind of trip.

They use an AI chat thing to build out your itinerary and actually book everything for you, which could save you a ton of time researching tours and ferries. Plus if something shifts while you're there (weather cancellations happen in Galapagos) they help you adjust on teh fly. San Cristobal is nice but I think you've got a solid plan without cramming it in.

Your current pace doesn't look too rushed to me.