Well, I got home today and made a little more progress. Thanks to MattC and others, I got my headlight relays squared away, and after pulling the battery from my FR-S, I have working headlamps!
I also added a little brake fluid yesterday, it was a little low. Tested my brakes again, and it looks like at least the driver's side worked. If the passenger came on it was too dim for me to tell from inside the car (no one else home to get a proper look!). But, when I accidentally slid the turn signal stalk getting out of the car, BOTH signals came on (like a hazard). It's the same whichever way I flip the stalk. Not my main concern at the moment, but I'll need to address it at some point.
While I still had the car on jack stands from changing oil yesterday, I noticed the starter ground looked like it was on POR-15 coated frame, not metal. So I sanded that down.
I decided to go ahead and turn the key and see what happened. CLICK. No turning. Took a couple tries, but then it did turn over

No gas line hooked up, and no ignition. Just wanted to hear if it would turn over. It was nice to hear. I tried one more time after that initial turn and it turned over again. So I'm calling today a victory, even if it wasn't all perfect. I have headlights, parking lights, some brake lights...and well, signs of turn signals. LOL.