4x4 or RS500 intercooler is a good idea.

Make sure its running 15psi held as thats what a stg1 car should.

Everything is safe unless setup wrong, if a piston goes its cause it was underfueling like a coont.

A well setup stg1 saff will piss a UK300 anyhow from a rolling start.

If u want more power then either a NMS super stg1 which would give u 300+bhp on std inj, or get a set of greeens etc and get a stg3 conversion- 300-350bhp (providing you get a T34 etc if you want more than about 300)

Breather system will come in handy at that power too.