Hey man, welcome.
Good to see someone else repping a manual trans for a bit of track work.
All I'd say is don't try and make the car fast on the track, it never will be. Just try and make it fun and reliable.
As for your heat soak, your only option is a bigger, better intercooler, and effective heat shielding around your turbo and manifold. Stock radiator and cooling system is usually OK. I don't know whether others have found an improvement with any of the aftermarket 52mm radiators