Of the three factors you listed before "etc," one could argue that all of those depend on factors other than the width of the blade. Size, much like grind, is all about personal preference and your own technique.
I have shaved with blades from 5/8 up to 8/8, from full hollows to wedges, and it's all about how you use it. I have to say, if I had to pick only one blade to use every day, it would probably be a 6/8 half hollow; a middle of the road razor in all regards. I love my big ones, but sometimes I want something a bit more maneuverable. And I have some smaller ones that I love, but sometimes I want something with a bit more heft and something that makes it easier to watch my blade angle.
A skilled shaver will be able to shave with any shavable razor. A connoisseur will point out the pluses and minuses of each shavable razor while enjoying every shave.