I also only buy the fly more kits so starting out with a minimum of 3 or 4. when flying a camera drone, I will probably only use 2 or 3 for that session but it helps to have extras if you need them even though I have a power station (charger)...
Unfortunately as a recreational pilot, you can only fly for fun and anything other than that, you need a part 107 to fly legally. Technically all drone flights require a part 107 but there is an exception when you don't need it and that's if you...
I dunno, I shoot 60fps all the time and I'm not finding it to be a reliable solution to some shots that suffer from blur or choppy. But then again, I rarely ever shoot at 30fps so maybe I'm just not aware.
You are free to shoot at, process...