Well, you've certainly done your homework. After taking the time to make such a thorough post I'm sure it's less than helpful to suggest you're over thinking this, but, that pretty much sums it up. My best advice would be to buy something - anything - close to what you've outlined. Don't sweat the details. Live with it for some time. Let your experiences with this first bike shape the decisions you make on the next. You've listed 12 items that each of us could express very valid reasons for choosing one way or the other, and not one of us would be wrong. Much of the info you're asking about is opinion based; a matter of taste and/or preference. There simply is no "best" or "worst," there is whatever's right for YOU. Only by buying, riding, and living the experiences will you learn what's best for YOU.
I going to contradict Skipjacks advice to buy something cheap. Too cheap is usually a waste of money. Your post demonstrates a fairly thorough level of research which suggests to me you could probably find something very close to what you're looking for. Close enough, in fact, that you will probably keep it as you buy your next, "more perfect" bike (n+1). Buying junk means you'll be left with nothing but junk to get rid of. Again, there's no right or wrong here, just opinionated advice.
Welcome to the disfunctionality that is BF. Keep us posted on your progress.
-Kedosto