How well does a 2007-2014 opel corsa opc/vauxhall corsa vxr grip in corners?

Let me clue you in. Even super cars barely pull any "g's", like only about 1.2g under max acceleration. You're mistaking centripetal force for gravitational acceleration. A diving airplane that pulls up sharply pulls g's. A supersonic fighter or rocket accelerating from zero to mach 2 in less than a minute "pulls g's".  A 192hp car does not pull any g's. 

As for cornering, the stiffness of the suspension, under-steer or over-steer, shock absorbers, fore-aft balance and the quality of tires has everything to do with grip. If the car you're looking at has generic factory equipment installed, it's nothing special.  If you want grippy, superb handling from an affordable used stock automobile, you can't beat a VW Golf GTI unless you're willing to spend a lot more money. In comparison, the Corsa is a slug.