1. I'm trying to identify whether the area highlighted in green in the accompanying image files is privately owned/managed, or the responsibility of Wokingham Council/some other local authority body.

I've looked at the original planning application for the flats on Ashville Way, but it isn't clear from the original application/plans where the boundary lies between the road surface/pavement/grass verge. I've also looked at the site drawing displayed by Southern Housing on their notice boards inside the properties - again the boundary is not clear.

The land highlighted green is not adopted highway and is not owned by Wokingham Borough Council. To find out landownership you would need to carry out a Land Registry search which details can be found at their website: https://www.gov.uk/government/organisations/land-registry