Well you just seem to know it all don't you?
1/ Mostly Ryanair will be tanking outbound so in all probability there is no immediate fuel consideration.
2/ Weather forecasts are sometimes wrong so getting confirmation of destination weather is usually good airmanship.
3/If a Cat3 approach is required it requires a monitored approach which may change the original plan.(Training requirements for example)
4/Ryanair go to many destinations where there is no ATIS or Volmet.
5/ Maybe they are asking Manchester because the ATIS isn't kept up to date frequently enough and nobody's talking on LPL twr? Asking LPL for RVR's directly blots out some other VHF frequency.
I work for Ryanair and although it has aspects which many including myself find unsavoury it is also subject to some of the most ridiculous bullsh*t!
