Basin and pedestal only fixed to wall and floor with a bit of sealant. Is this normal?

No just lazy

no they should be screwed to wall.

Absolutely not. Must have a mechanical fixing into wall and floor for secure placement. If you look beneath the sink you will see 2 the fixing holes for the fixings. Alternative fixing method are to use 2 x single steel brackets that the sink will sit on fixed to the wall There are 2 more holes at the base of the pedestal to be fixed to the floor. At the inside top edge of the toilet cistern there are 2 fixing holes to be used Theses items need to be secured correctly, unfortunately you have not had a professional carryout this job.

Basin should be screwed in case it’s pulled from the wall but toilet can be stuck to floor as there could be pipes underneath when screwing

Hi, both the basin & cistern should be attached to the wall with appropriate fixings, not sealant. If down the line these need to come off then there could be issues with releasing them and this could cause damage to the wall or fittings. There are screw/bolt holes on the furniture for a reason and in my opinion the way that these have been attached is lazy. If a job is worth doing its worth doing properly.