Obviously, a beetle floorpan uses an aircooled engine.

However, because i intend on getting one in the future, how likely is it to overheat the engine. (Even if your really flooring it).

Are there any kits or forms of SUPER cooling that can be done? (Any radiator mods etc.)

A well tuned VW engine should rarely, if ever, overheat.

A VW (or any) engine thats worn out, rarely serviced and badly out of tune will be more likly to overheat

As for cooling, there are no radiator mods, because there is no radiator.
common mods for cooling are a dog house fan shroud (if you have an earlier engine), external oil cooler and most importantly a well tuned engine.