I think "too warm" is going to depend on the individual. If you're from CO it might be a little warm. Humidity is definitely high. If you're there for a long time you start to get used to it; it not, you won't. We just try to limit our time "hanging out" outdoors during the day. Even then you will work up a pretty good sweat if you're doing anything. Lots of folks LOVE it....we're dry landers and love it there but prefer winter.
Bugs, snakes, alligators...all are part of FL. Bugs can be an issue and I've seen the biggest roaches?/water bugs I've ever seen in my life there when looking at houses with the kids. Snakes are there but only if you're poking around out in the boonies. I will say that puppy found what I thought was a stick but she was way too interested so I called her off. Turned out to be a pygmy rattler (I'd never seen one) and it coiled as soon as she pulled away. Very non aggressive and small (maybe 12"). Gators are just there. Don't see them a lot and don't think about them. Unless you just go looking for them, or let your dog romp in the water - or near the water, I doubt you would know they were there.
Back to bugs. Our biggest dislike in the summer are the no see ums. You can't get out in the evening without being swarmed by them....and they bite. Insect repellent helps but sometimes they still get so thick you breath them. We love to be out in the evening but those things can ruin the day if you're not prepared. Being close to the water will help. The breeze sort of keeps them at bay - they are so tiny.
All that said, just go prepared. Sunscreen if you want to be out a lot or on the water. Insect repellent. The more DEET the better for me
Camp close to the water if you can but you don't have to. Take your fishing gear......
All kinds of stuff to catch.
Make your reservations early. People camp there (FL) year round. Winter is more popular. Panama City is nice but kind of busy. If the kids live there that may be where you want to be. To the east (Mexico Beach, Port St. Joe) it's more laid back but fewer amenities - in fact not much at all.
I've just given some of my observations. We love it there no matter the time of year so not trying to dissuade you - in fact my recommendation is to go. The 2nd AC is a definite IMO. We're from W TX so used to the heat but the humidity just drains us.
We've been fortunate enough to spend countless days/weeks/months with our grandkids when they were out of school. It's nothing like when they are going to school and we have made SO many memories that all of us remember because we spent days on end doing stuff together. As I said, we're in W TX and now follow them to FL every year for several months. Sounds like you're in CO and want to follow yours to FL as well. When making a trip that far you want to be able to spend as much time as you can with the grandkids ......so, make your plans and get on down there......with DEET and antiperspirant in hand
I'm pretty sure you will have a blast.