Hi Cobby, with regards to scaling the overlay of Blackpool, you want to have your scale on google maps set to metric, so you'll have a scale in metres, then consistently adjust the number in your overlay settings found under file/preferences/overlay. Once your scale bar matches up with the appropriate value in NoLimits 2, you'll have it scaled correctly.
As for the plans for The Swarm, you need to ideally get Sketchup Pro 2015, draw a rectangle with the dimensions of the scale (so if 1/500 at A3, draw an A3 rectangle, then scale it diagonally 500 times). Then apply the plan image as a texture and again scale accordingly. Export your Sketchup model (just the rectangle) as a Collada file (.dae), then create and NL2SCO in NoLimits 2, set the Collada file as the object path, and place the scenery object in an empty park file. Scaling plans like these are near impossible with the current overlay customisation settings.
If you need the plan making drop me a PM and I'll be happy to sort it for you