The Manchester shuttle will never work. The train is frequent and 2.5 hours cheap deals can be made.
The Scottish Islands will not work. As someone of that heritage I know very few people who have visited there from the NE. A lot of people bring their cars and explore the area as a whole as let's face it you need a car when you're there and SYY town can be done in a day for a tourist.
Anyway, a flight from MME will not work. Eastern sell connection the SYY via ABZ anyway, I very much doubt there is enough demand to support a dedicated air service. Yes people do visit, but not in great numbers. SYY does not have any links to England, I very much MME will be first on the list! Same with LSI (save for the odd seasonal and irregular Atlantic Airlines to STN).
Some suggestions are rather fanciful I see here. MME has it's niche. It seems to be working for them as it is. They're never going to be a major player. They have a domestic to ABZ which serves the demand and KL allows connections throughout the world. It has all it can feasibly support minus perhaps the non airline to IOM or weekly JER flights.
If there was oil traffic to be capitalised on then T3 would be on the case.
The London links have been discussed to death. They didn't work for BD with their feed via LHR and will never return and LCY won't work