Dedicated lines are a great upgrade. Based on all of your questions and rules I think it might be a good idea to get some help from an electrician. Donβt overthink this, plain copper will do the job.
What wire to use instead of Romex
I want to install a dedicated 20amp outlet (likely an AQ NRG). The run from the main panel in the garage to my living room above is relatively short - maybe 25 or 30 feet. Because of HOA rules/regs, I cannot use Romex. Wires in the garage must be inside conduit. I will run 10AWG, but I'm unsure what other specs I should implement. Should I use solid core or stranded? Should it be copper? Is BX the way to go? I've read where using stranded silver or silver tungsten is best, but I'd be concerned about the silver oxidizing/tarnishing over time, especially at the junction points where the wire has no insulation. Is it important to twist the three (including ground) wires or will they perform just as well if run side-by-side?