No! Don’t use pink stuff paste or a magic eraser! Pink stuff spray is fine but not the paste. We have spare doors at work and have done tests on them. You should not use a product that is harsh such as paste because in time it will take the surface of the door off. If however your doors are so bad that they are ready for replacing you have nothing to loose. I’m now monitoring the removal of marks with baby wipes. For some strange reason they seem to shift a multitude of sins.

Hi, first I would think about drainage. A flat surface will hold the water and you would have the same problems as before. I would slightly raise the back (1 inch should be enough) and have a small overhang at the front so that water won't damage the front of the cupboards. Some marine ply or tanalised timber covered in shed roofing felt should do the job (see image, but angle doesn't need to be as high). Not as good looking as Daisy's roof tiles tho:)

If the door is being hinged as you say then i'd have a vertical handle. Depending on the type of handle you've decided on, having all horizontal handles works fine in a galley kitchen but when you have an L shape the doors in the corner can get damaged by the handles of the adjacent doors when these are opened. Looking at the pic it looks like you're having an american fr/frz to the left of the oven tower and the top box looks like its stepped forward so a large horizontal handle could possibly hit the top box assuming the door is hinged left. If the vertical handle doesn't look ok with the symmetry of the kitchen then you could opt for a lift up door with servo drive by blum then the door would open and close at the touch of a button.

My experience of local councils is that they don’t know their bottom from their elbow. It’s not good enough to stare you need a certificate when they are unclear about what they want the certificate to say. Ask them to direct you to the exact regulation that says a fire door is required in this situation. Firstly it sounds like you have a cupboard for your washing machine not a habitable room so you may not need a fire door because it’s not a room. Also fire doors are used to protect the stairs so people can get out of a three storey house- if your house is two storey or the utility cupboard is off a room that already has a fire door then the requirement is unnecessary. And the regulation will help you understand what they are looking for in order for your door to comply (most likely 44mm thick, rated door frame, intumescent strips, rated for 30 minutes protection etc).