The ground cable is actually 4 AWG.... and about 3 inchs in length, hiden under the carpet running to the distrobution box on the left hand corner, opposite of the 12V+ 8 AWG.
you have made that "wiring panel" far more complicated than it should be. and the whole thing looks like a big fire hazard to me...
1. the first issue I see is: you have a large power cable (8awg?) as your main power, which is fine; but I don't see an equally sized ground cable, in fact all I see is a tiny little black wire leaving that "panel". aside from the fire danger that running a tiny wire poses, it may also cause some or all of those devices to malfunction.
Its bigger then the powerwire. 3 inchs in length. It is connected to a huge bolt connected to a heavily sanded area of the frame.
1a. your ground wire needs to be as big as your power wire (or as big as all power wires together). your ground cable should be as short as possible and should be secured to a clean (unpainted, uncoated) metal surface of the car body/chassis. you can connect it the floor right next to the panel, or scrape the coating off the seat bolt/nut and ground to that. you can use a distribution block for the ground wire if you want, but its not necessary.
Im not having issues powering the devices, just dont want to blow out any devices. Infact it is running very well, not like my first install that had a bad ground, caused everything to run slow. Thanks for the advice though, I really dont have the room or time to redo it specifically to your method (the running a 8awg accross the terminals). This picture is actually old, I have tons more cabling now. I'll be surprised if the seat is able to go back on.
2. for that setup there is no need for power distribution blocks. your fuse panel should have a single [main] power cable feeding it, this way the fuse panel takes care of power distribution and all wires are individually protected (assuming your main power cable is fused at the battery).
2a. since the fuse panel you chose uses individual terminals for each fuse, the easiest way to run a single power feed to it is to strip enough insulation off the main power cable to span across all fuses. then solder each terminal on the right side of the panel to the power cable. this will give you 8 individually fused power outputs from a single main source. you can leave 1 fuse terminal unconnected to the main power cable to use for the relay coil power input.
good luck :)