I don't think you are in the minority among rally fans. At least poor Colin planned to make some road version of the R4 to sell to the public...
FIA changed it and both tuner and manufacturer = constructor. So they just can develop it on their own.
Quite possibly. Jon Armstrong isnt an 'Irish name' and he's from Kesh which is 77% Protestant with 72% having a British identity. https://en.wikipedia.org/wiki/Kesh,_County_Fermanagh

The rumoured new Celica is a low-slung sports coupe. A WRC27 version with the new (taller than Rally1) spaceframe ? Are you sure you dont mean Corolla ?
WRC mainclass from 2027