SPA disconnect switch grounding wire requirement

Hello, I am wiring up my spa and looking at what info I have (GE / Cutler Hammer) they say for a spa (240) use a 50amp breaker (which I have) and use 8/3 size wire. But looking at my spa where you hook the power up it says use 6 AWG minumin? So which should I use from the house to the breaker...

I am having a 36,000 btu split system installed. This unit is 230/208v with 30 amp breaker. Instead of using the pull out style or lever style disconnects, would it be safe to use a 30 amp 120/277v a/c double pole toggle switch mounted in a appropriate weather proof box as my disconnect?

I just changed the air pressure switch on my SpaBuilders controller for my spa. I noticed that the bare ground wire attached to the left side of the controller was not attached at the other end. I searched, but could not find a likely place to connect this. Where shall I connect this ground...

I purchased a used spa from a friend. I am ready to run my electrical connections but I noticed the pig-tail that is on the spa has three 6 or 8 Gage wires for hot and common but the wire that I assume is the ground is only 12 Gage or so. Is this because the ground wire serves only to trip the...