Tumaini and I are also going to Florida soon! Traveling with a baby or toddler is awesome, you can take the express lane, and they're more lax when it comes to liquid/food rules. I'm pretty sure most sippy cups would be accepted, especially if they see your kid drinking from it.
I totally forgot I had a sippy cup full of milk when we went through last time. They said they were going to check it separately, but I think it just went through the regular machine. I meant to dump it, but it ended up not being a problem after all. I've also had zero issues traveling with the food pouches.
Yes, you can bring milk, baby food etc. As much as your baby needs, you just have to let them know about it as they might run a test. I actually haven't brought milk myself for her...but I've brought baby food and it wasn't an issue.
Re: Traveling with a toddler ?