I’ve been every year and it’s a brilliant festival.
You won’t be able to drop your stuff off at the gate and then do the park and ride- the roads immediately outside the venue are closed and you’re basically compelled to do the park and ride. It’s very well organised though- there’s hundreds of buses doing shuttle runs and they will load and unload your gear for you. The bus journey is only about ten mins anyway.
As far as I’m aware small gas canisters and the like are fine.
You’ll have a brilliant time- make sure you check out the woodland raves. They didn’t used to show these on the maps etc but I think they did last year so should be easy to find.