Im glad to hear he's eating a little better. I keep praying for him and for you and Chris to be strong for him. You are the best bunny mommy and daddy in the whole world- hes such a lucky boy.
Im sure the vet will examine his legs and his spine area. I would also ask about his kidney function (which would also be good to check due to all the extra fluid he had accumulated).
Did you guys weigh him once the fluid was drained? Id be weighing him weekly to be sure you can tell if its coming back.
Sending lots of love, virtual hugs, and prayers to the little man
Haley