In Ryanair when pax numbers are below a certain level a few seat rows are blocked off to help with the c. of g. This is necessary because they only use the forward hold for bags as this saves time on turnarounds, the rear hold is only used when the front one is full. Ryanair do not carry cargo except company stuff e.g aircraft parts.
The fuel tankering policy works as follows:
The aircraft can be operated at three different MTOWs, 66990, 69990 and 74990kgs. It is usual to set the MTOW to that which is required for pax load plus planned sector fuel. Fuel is then tankered up to that MTOW (or max landing weight plus trip fuel) e.g
aircraft weight including pax and sector fuel 62500kg
MTOW 66990kg
approx 4500kg of fuel can be tankered.
The MTOW is not usually changed and pax are not off-loaded to enable tankering. On long sectors they usually plan to land with no more than 5000kgs of fuel on board to avoid having to de-ice due to 'cold soaked fuel frost'.