if you could take a pic of that relay untaped that would be great because im not seeing a reason to have a relay period in your current situation.
If that ground is where i think it is in the trunk of that vehicle then he is on the frame or very close to it and definately part of the unified chassis. I would def remove that paint asap it will likely assist in your atl whine issue. Also what gauge wiring was used for your ground wires...i cannot tell by the picture but it looks an awful lot like 8gauge for both if that is the case im going to need you to upgrade that as well. As for the saftey issue do whatever you feel is safest. I personally never disconnect batt terminals unless unplugging airbag harnesses. As for the distroblock i strongly suggest you purchase a decent distro block and run at least 2ga to the rear of that car and then split to at least 4ga to the 1000/1 and the kicker. As for the big 3 upgrade i would also do atelast 2ga if not 1/0. The wiring in your vehicle seems more lazy then anything else or like someone was attempting to quickly complete the install.
I'll definitely take a picture of the relay without tape tomorrow during the day.
The gauge of the wire for the two amp grounds is 4 gauge. as for the ground used in that Bosch relay thing its a very small wire probably the same size as a remote wire.
I think I'm going to follow your advice and upgrade the power wire gauge and distro block.
Do you recommend any places that sell these wires and distro blocks(any recommendations on specific brands)? home depot? or something like that?
thank you very much for your response