I think the points you listed are really personal preference, and whether they bother you enough that you would want to look at a different jacket. I had previously purchased the WM flash jacket (Wm S, 8.92 oz wt), but returned it for a MB Alpine Light Parka (M's S, 14 oz even)- it fit much better than the women's version for me- longer, more fitted torso and sleeves) for a few of the reasons you stated. Those points bothered me enough that I was okay with a 5 oz weight gain. ymmv.
-The sleeves seem a bit short as they stop just before the hand.
Is this to allow room for gloves?
What is the ideal end point for sleeves when the arms in a relaxed position at one's side?
How much extra length, if any, is needed for them to ride up when moving them?
I think that this is a very subjective thing. I like to have the sleeves long enough to just hide my hands in if need be when it gets colder.The WM sleeves were not long enough for me to do this- M's small or W's medium.
The jacket has an elastic band at the bottom that keeps it pretty snug to my body. However, it always ends up exactly right above my pants.
-Once there it stays in place, but is it supposed to cover any part of the pant, or is that the job of the outer shell (and the pants of course)?
The elastic band fit snug on me as well, but would ride up a bit when i sat down or moved. The MB Alpine light has a draw cord so I could cinch it a little looser so that it wouldn't do that, but still provide a close fit. It helped that the torso length was a bit longer as well for me.