Here is a link to the TSA stance on remote control vehicles.
This talks about batteries
I have flown a lot with rc stuff and I never had an issue where my stuff was taken or not allowed. Not that I recomend it but I have flow with motor spray, paint, lighter fluid ect in my checked bags. I always carry on major electronics such as power supplies, GFX, batteries, and raidos. The reason for this is that it weighs a lot and I can pack more stuff for checked bags.
There is no doubt
when you put a GFX through a x-ray scanner you are going to get a bag check so arrive a little early. This has happend every time to me with out fail. Once when I went to Vegas they saw the GFX did a bag check and swabed all my stuff. My Ott light had some explosive residue on it so that got me a little extra pat down but I was still allowed to carry it on. After that I wipe all my stuff down prior to travel.
When you fly home out of Orlando (MCO) they are pretty hip to r/c stuff and in most cases TSA people think it's cool. One year from snowbirds I had a case of Nimh cells (10packs total) and they wanted to screen it. Once they opened it (they thought it was poker chips) and I explained what they were they wanted to know why I had so many? Once the head TSA guy came over and looked at the batteries and I explained what I did he said "oh yeah i've been dealing with you guys all day", he took a pic and let me on my way.
Just be prepaired to be stopped and checked, arrive early, and be NICE, no one wants to deal with a jerk off or an ass hole. LOL