My comments:
Really really good read on the original build thread. You had me reminiscing on my build done in 2013-2014 (which I am now rebuilding engine) I wish I had done a build thread but heres a youtube I did on my baby:
The father and son Integra build is awesome. My Dad taught me how to change oil but I'm mostly self taught, I actually showed my Dad how to do an engine swap a Del Sol. Yeah the 17's on Integra's can have a tendency to ride hard and wear funky, just reminds me of how different things were in the late 2000's and 2010's. Glad you got the ant queen! I hate ants, they always end up taking over sitting vehicles. I've battled them many times as well as interior mold. Pretty cool on how you found the key. So did it sit after the suspected head gasket issue?
Possibly helpful:
I noticed the corrosion on the pins you probably know that corrosion can cause high resistance preventing power from reaching the load (fuel pump). Or maybe check the main relay under the drivers side dash, could be corroded inside. Might want to check the hanes manual for wiring diagram for the fuel pump and start checking those circuits for a loss of power or ground. Also I think you should attempt to jump the pump to see if it actually runs, even if it does you might want to pull it for inspection.