Re point A.
That doesn't just happen to councils, in Nottingham IIRC Games Workshop built a big new factory complex having apparently been told there was power for it, then had it sit largely idle for a long time as when it came time to hook it up the electricity board didn't have the capacity (I think due to other construction) and if what I've heard is true basically said it would cost many millions to do the final hookup as the company would have to cover all the cost of the additional works needed to upgrade the incoming supply.
In the end I think they put a load of solar up on the roofs of their buildings and waited for the electricity board to build the capacity for other projects.
A lot of construction projects run into real issues with things like utilities as the likes of the electricity companies can charge you for any upgrades they need to do in order to supply you if they are above the normal stuff, and whilst they can state when you are planning your project that there is capacity, they don't have to reserve it for you, and can use it for other projects that get built before yours or if they run into problems themselves.
There is a very good reason when the likes of a supermarket gets an extension they would often also spend the money to update all the existing lighting and other electrical appliances as the cost of getting the electricity board to increase their supply can often be 7 figures or more (the fact it also reduces long term overheads also helps). IIRC the cost of moving from one level of incoming supply to the next level up can be absolutely eye watering, even if it only needs a line from a nearby main substation.