In terms of the Windows Store, I would categorize the apps into 2 segments both that get problems when updating.
1. Apps that can be deleted and reinstalled.
- These apps were probably installed when the Store had both "Store" and "Store Beta". Like my office apps for example, i had problems updating them. I tried allowing the phone to default install from "Internal" to "MicroSD" and still it didn't work. However, after uninstalling and reinstalling it. It worked fine.
2. Apps that are not available, but appear updates. (Could be system apps)
- These are abit more curious, i think. Such as touch, audio, info+ ..(can't recall if that's how they are named). What i can remember is during WP 8.1, you could installed these apps for some additional tweaks, since Win 10 TP they have been removed but they still appear in the store and there's no way of deleting it (not that i know of at least).
- If anyone knows how to rid these, do sound out as well. Would like to know too. Hope this helps abit.