I have a 1.9Tdi Golf Estate 97 on a P plate which recently had the cylinder
head go. Other parts of the engine were dying so I replaced the Engine with
another 1.9Tdi same engine codes so it was a straight swap.

Now i drive the car pretty car and was wondering if my style of driving
could've been the culprit for the cylinder head failing, all the excess heat
etc.

So my train of thought has come round to Intercoolers, I know they are
designed to cool the charged air that enters the engine thus making it
denser thus allowing more fuel, which in turn increases the power. But what
I would like to know is would a bigger intercooler help keep the engine as a
whole cooler thus reducing the chances of the cylinder head dying again.

Or am I completely barking up the wrong tree?

Cheers
Dave