For a start, you will not join a school like Oxford, BAe, SFT, etc. as an instructor on the approved IR course unless you have considerable previous experience. When you get to the IRI stage, there is no such thing as a 'CAA' course, you have to complete an approved course of training and a Skill Test with a FIE in accordance with JAR-FCL 1.330. In the case of Oxford and SFT (the only schools of which I have personal knowledge), the standardisation course is far more thorough than the JAR minima, as is the Skill Test.
[This message has been edited by watford (edited 12 January 2001).]