Naughty,
Yes and yes
.
Firstly there is no problem with logging the hours towards licence issue, as long as you hold the pre-requisite requirements, which it appears you have. Also make sure you have the night qualification and have completed your 300nm cross country flight. If my memory serves me correctly, if you don't hold a night rating then you must do the 5 additional hours night instruction for the issue of your CPL.
With respect to the time limit, as per LASORS you have 12 months from the date you pass your CPL skill test to get your licence issued, which should be no problem if you go staright onto the IR. In fact, if you wait until you have your MEP test and IRT done, and get the whole lot issued together i.e. CPL MEP class rating and IR, it will save you about £250, or 50 minutes in a PA34 Seneca
.
Enjoy it, its a good course.