as far as I am aware full ILS approaches can be carried out
That would be using the nav receiver in the GNS 430.
The database will have NDB, VOR and LOC/ILS approaches which can be loaded into the flight plan but it is not legal to fly these approaches using the GPS as the primary means of navigation. The ADF or nav receivers must be used as the primary means.
How many GPS approaches do you have in the UK? I read recently that you only got your first GNSS approach last October.
It is true that GPS approaches will only be at airfields that have ATC? This seems a silly restriction. What is the reason for this?