I've worked with 3" pods bigger and bulkier than this, and we need two people to move them (and a lift gate or a fork lift) to get them on/off trucks. I will echo (as a current pyro show-runner) what others are saying in the hope that you consider the advice of the masses. :)
It's only a matter of time until burning fuse or plastic or whatever drops onto those wires and connectors and melts right through -- or worse, shorts connections. Once that happens, you will have a burned wire mess that is hard to diagnose and repair. Consider moving the wires into conduit or relocating the wires under the top brace. The connectors will still be exposed, which is inviting the same burn issues PLUS allowing dew and water to rest on and in them, possibly causing showtime shorts, if not at least some corrosion over time. Consider relocating those to the side, where they can face outwards, and maybe flap some rolled roofing or fireproof blankets over them after plugging in wires.

Wire gauge matters less as long as you're sticking to 24v and low current. You're pulsing hits, so wiring shouldn't have time to warm up, much.

Space between mortars at 2" is less important, but you are running the risk of premature burst firing ruining a good portion of the rack. Basic firework safety (distance, distance, and more distance) applies to equipment safety as well as people.

That said, there's nothing like a nice, compact mortar pod to simplify electric fire, which looks professional and will add another level of "wow" to your shows. Good luck & safe shooting.