I agree on the maintenance! Since I did the temporary repairs I have kept the gutters cleaned out for the most part. I don't think they have enough slope either toward the downspout.
I want to use the hidden hangers for the new gutter. I'll see if the back edge is higher - it would certainly make sense. If the vertical leg of the drip edge were long enough, I could set the entire gutter a little lower.
It just seems like a vulnerable area. The other idea I had was since i am getting metal bent for the fascia wrap, do people ever bring that one-piece metal up onto the sheathing? Say use a 10" wide piece of coil stock, bend the bottom 90 so it's 1 1/2", then bring it up the fascia and bend it back to match the roof pitch over the sheathing, then I&W overlapping it. My only concern would be expansion and potential for buckling.