Re: MEP rating renewal
If you renew your IR on a multi engine piston aeroplane the examiner will sign off your MEP rating at the same time. If you renew your IR on a FNPT sim then you'd need to renew the MEP class rating separately on the aircraft.
Once you have done a multi pilot type rating you need neither your single pilot IR or your MEP rating. During your initial type rating course you will take an LST and be issued with a multi pilot IR and the relevant type rating.