Apologies for the length of this and the amount of questions. I have now built a very basic robot, after lots of reading and messing about I have something that drives and has a pneumatic lifter. I was going to use a linear actuator but just couldn't get the lifter fast enough. I have learnt a lot from various threads here but some posts get a bit technical and some answers seem to contradict each other. I assume that's due to some rules changing over the years or different ways people interpret compliance.

My questions are regarding making sure my final design meets the safety requirements of the rules, now I know I can get it working.

Electrical
1 - I have a removable link (a fuse in a holder) how do people make it accessible from the outside? Just a flap on the shell? How is this kept closed so it doesn't come off in battle but is still easily removed when needed?

2 - how do you test that the receiver failsafe works? There's a light on my receiver. Turn on the transmitter and it's on. Turn off the transmitter and it's off. That shows the failsafe is working, right?

Pneumatic
The rules aren't very clear on what's needed here. To me at least.

3 - I'm using a paintball Co2 tank so assume the burst disk on it is all that's needed between it and the regulator to comply with the pressure release rules?
4 - the regulator drop's the pressure so that it's below the 10 bar limit of my ram. So in this section I need a 10 bar PRV that'll open and release the pressure if it goes above 10 bar for some reason? Can this be anywhere between the regulator and the ram?
5 - I believe I need to add a QEV to dump all the gas in an emergency. Is that correct? This also needs to be accessible from the outside? How do people achieve this? (similar to Q1 regarding the access flap/panel)
6 - I need an on/off so that there's no pressure in the system until it's in the arena about to battle? Can this just be a simple on/off valve after the regulator accessible from the outside as the QEV/removable link?