It's a shame you had such a lot go wrong on one trip. I can understand you're not being happy with the ant problem ( IMHO bugs in general go with the territory in Fl, but ants are definately not nice), I tend to agree that the most likely cause was a previous guest leaving foodstuff around. Once ants find a foodsource they leave a chemical trail for their coworkers to follow, that trail can still be active weeks after the original use and even if it's sprayed there can be recurring problems. It's one of the reasons I'm always VERY fussy about leaving food about but with young children ( and I'm not blaming the OP, I think it more likely it was a previous guest) spills are not always cleaned up and can lead to these problems. I'm not sure what a hotel chain can do about that type of problem, in Florida I think that's always a potential problem.
It's horrible when your child is sick on vacation, I think some people got a litle confused in your posts and thought you were blaming Disney for that, it took me a couple of times reading through to work out you didn't mean that.
I'm still confused on the child injury thing, was the child ( age three am I right?) sitting on the floor colouring and somehow got it's head stuck in a gap, or was it sitting up on the bench seat alone and fell/stumbled/slipped getting it's head stuck? Not sure if all the units have the same seating as I remember , but I'd have thought that was kinda high for a 3 year old to use for that purpose.