hiya m8. In the n/s & o/s footwells behind the kick pillar trim, there are focus & focus RS main earthing points bolted in via an 8mm bolt. Check that they are all tight, check fuse box and pull out KAM fuse & replace to reset module memory. Bit of a guess, but that might be your prob mate.
Car not going over 30mph and running lumpy is because it is in Limp mode to protect engine damage. Hope this helps!!