there a couple of things I would change.
1: Personally I don't like the guild store pop-up feature. I honestly think the way UFSG is set-up would be ideal. ie. once you hit the backpack manage page you can find the item by name, set, stat type, rarity etc. If not that then maybe the AH which also gives you the ability to search by the type of item, rarity, craft, hell forge etc.
2: When it comes to the backpack manage page... maybe it would be better to just indicate something is guild locked instead of excluding it.
3: From the character page: I would like to be able to pick the amount shown per page.
4: From the character page: As has been mentioned I believe here and on the next roadmap- the ability to custom order your backpack. For example. I would like to keep my offline gear at the front of my "storage" folder at all times.