Biggles78,
Re your questions about the CofG, this diagram should help you to visualise the CofG "corridor".
It's the one for G-AXDN (01) but the production one is closely similar.
To make some more sense of this.... all those percentages quoted are in terms of the "wing root reference chord".
Mentally cut the wing off the fuselage and measure the length of the cut (including the elevons)..
That's the "root reference chord", and it's 27,76 m.
To give you another reference point: the main gear attachment point is located at 57% ""root reference chord".
So any CofG beyond 57% on the ground, and you have yourself a tailsitter (it's happened)..