How much does your kid like animals? We could never go without visiting AK. It is an easier day in the park. I would consider adding another day, and making AK your easy park day with pool/relax also. No reason to rush in this park. Walk around, watch animals, goto conservation station and do the animation drawing. The safari is so neat for anybody. You could spend an easy 4-5 hours here, then spend the rest relaxing.
Much cheaper to add another day than to jump to Universal, where I'm not so sure a young one will enjoy. Then you have another day for MK, and it can also be a more relaxed day since it is your second day back to that park.
You have a LOT of eating planned. For a first time in years, and having to travel to places that you are eating, that is a real time drag. The good part is that you get to relax a little for a sit down. Since you mention that you are Covid nervous, the sit down restaurants may be the biggest threat. When we went in DEC, we did not do a single sit down dining. Disney is doing a great job of cleaning and spacing. We felt much safer than a trip to the grocery store.
GOOD LUCK