With a dessa pitch it does need light and specialised clear roofs will help with this. In winter there are options to use lamps that sit just above the pitch to help the grass grow, similar use at Old Trafford.
With staying at AG I can see a hotel eventually being built on land currently used by the BCCT on match days in the Hirerite building. They can use this area as a hotel.
With retail, this is the area that will be lacking staying at AG as there is already a retail park next to AG plus there is no room to build.
As for buying houses backing on to the Ateyo. I don't think that will ever happen.
MM