I'm a lefty shooter and have been seriously looking at buying a PCC some time.
1) Option 2, I don't care about ambi ejection ports. Brass flying in front of my face is fine as long as it doesn't fly into my face.
2) Depends on question 3. If it's a side charger just keep it to the right, if It's AR15 style charging go ambi.
3) Don't care, so long as it matches my response to question 2.
4) Option 1, though not having it wouldn't be a deal breaker.
5) Option 1, within reason for price and solid construction.
6) Option 1, again within reason. Not looking for a $2500 fancy skeletonized PCC.
7) Option 2, unless somehow carbon fiber wrapped barrels wouldn't be a lot more.
8) Option 3, rails add weight, are less comfortable to grip, and I don't plan on loading on accessories. Maybe just a small section up front for a front sight like this
https://www.rainierarms.com/media/product/0c3/slr-rifleworks-14-solo-ultra-lite-ar15-handguard-mlok-14ml-ul-by-slr-rifleworks-d4c.jpg. MLOK over keymod too, if it came with keymod I'd want to replace it which I would then have to consider the added cost of doing on top of purchase price.
9) Option 1, but I get the practicality of option 2.
10) Option 2 preferably, Option 3 if I like it a lot. What I'm willing to spend would be dependent on how it matches up with what I want.