my son and my youngest brother and sister are at a Catholic voluntary aided Primary school (son and sister just finishing year 4, brother just finishing year 5).
The school is fantastic and very supportive. In his school they have hymn practice once a week and mass on holy days of obligation, once a week in lent and advent and at the start of term, they also have masses at the church for christmas eve, easter sunday and mothers day, but these are optional. They also say grace every day.
The school rules are very much based on just generally being a nice child and say things like 'i will be nice to other children' and 'i will be helpful' and at lent they are encouraged to do write and keep their lent promises (stuff like i promise to put my toys away without being asked). The infants Christmas plays and yr 3/4's easter plays are obviously very religious but are generally quite cute and funny with lots of terrible jokes worked in, yr 5/6 end of year play is not religious at all
His school don't spend a massive amount of time on RE as a subject but they often work bible stories and morals into the other lessons and they have the option of going to the chapel for rosary at certain times in the year and in year 3 the children who go to church regularly have some extra classes if they are doing their first communion.
The catholic school they are at is the only 'outstanding' rated school in the area so has a lot of non-catholics there (as in at least 1 in 3 children are not catholic) and even more who go to mass for a few months before admission to get the child in then only appear at school masses once their child has started.
Their school is quite strict on important things like being nice to each other and trying your best in lessons but imo all schools should be.
They aren't amazingly strict on uniform (except girls shoes being sensible) and their uniform is a jumper, polo shirt and trousers/skirt so no different to most primaries.
All in all it's a pretty amazing school.