Smith - you could have answered all your questions using LASORS - read that first next time.
LASORS E1.2
When applying for an IR(A) you must produce evidence
of having met the following flying requirements:-
50 hours cross-country flight time as PIC in
aeroplanes or helicopters, of which at least 10 hours
shall be in aeroplanes.
You must also have a night rating as also detailed in E1.2
LASORS D1.7
An applicant for a JAR-FCL CPL(A) shall hold a valid
JAR-FCL Class 1 Medical Certificate.
FULL DETAILS OF MEDICAL REQUIREMENTS
ARE CONTAINED IN JAR-FCL 3 AND SECTION A5
So therefore you need the Class 1 for CPL issue but only Class 2 for training.