Sounds like a fun challenge
The edge blending will be a pain in the proverbial, could you get away without it?
Maybe just use one projector for each wall, or one for top and one for bottom of the upstage wall.
The Datapaths do just need programming once so should not cause any issues.
I would suggest using both computers and splitting the load between scenery mapping and control booth screens.
I hope the tiles are not shiney.
Also 10:16 would usually be 1200x1920 pixels