I'll try and answer these...
JAA CPL and JAA IR training cannot be combined.
They can be done one after the other.
If you have a JAA CPL already then your JAA IR course will be 50 hours instead of 55 hours for a non-CPL holder.
Reality in obtaining a JAA CPL in 150 hours? NONE. None whatsoever.
The reason? You require at least 150 hours total time including 100 hours of P1 to START the JAA CPL course. The course itself is 25 hours.
For licence issue, you will require at least 200 hours total time including the JAA CPL course and flight test passed.
Don't forget that before you start the JAA CPL or IR course you will need to have passed the JAA ATPL (or CPL) writtens exams.