1: Do I really need to keep a min 1" ID?
No, but I find it helpful.
2: The walls this hive will most likely live on all face north and receive virtually no direct sun, so the entrance won't get any.....does it matter?
Probably not. I've had OHs facing all directions. It works out.
3: How much of an issue do folks find trash at the bottom of hive?
A strong hive will take care of it.
Is some sort of screened bottom/tray worth while?
I put one on my last hive, but it isn't necessary.
4: I can see top entrance helping with keeping the dead from clogging it up...but might it provide too much ventilation in this case?
Bottom or top works fine. Too much ventilation can be an issue, but that largely depends on your location, humidity, sunlight, and design.
5: does light penetration via vents need to be addressed?
No, but light penetration via windows does.