I’m like you in that I use Ancestry as my main point for research and then use RM as a backup, and use all the great tools to check for errors etc.
Jerry & Renee are correct in that there is not a lot RM can do with Treeshare (other than to continue a dialogue with Ancestry) as Ancestry control what features their API will work with.
Re your point on “Abolish Update Screens”, I don’t understand why you have raised this as RM9 does include a single check box which when selected will add all the fact updates for that person in one hit. This feature was included in RM7 but dropped in RM8.
Re your point “Improve Functionality”, there is a post from Renne regarding the issue over updating Place names, where a process will trigger that change in Treeshare. You can find it here
Place Name Merge and Tree Share - RootsMagic - RootsMagic Community
Overall I find Treeshare very helpful and easy to use, once you understand its limitations.