There are obviously lots of peeps on here used to driving powerful FWD cars, but I think the Cupra has too much power already and that a remapped one would be a bit of a mess. Mine will spin its wheels in the first 3 gears if it's damp or cold. The handling is pretty good, but not Golf good because the ride is a bit on the stiff side. Nowhere near as bad as the mk2 Leon, though.
The first mod I would do is change the 19" wheels to some lighter 18s, as the handling is so much sweeter on 18" rims. Of course, if you're wanting a manual 3 door then you could look at the 265 version. Second mod would be to uprate the dogbone mount to tame the savage wheel hop. Then maybe consider a remap!