Bathroom tiles floor-to-ceiling or half-height tiles?

The baseboards are more intended for the living areas, so the hallway (door to the guest WC) and at the door from the hallway to the living room

You can make the baseboards yourself.

I would very much prefer not to stick the wall tiles myself (I haven’t done that yet) and will I be able to match the grout color of the other tiles in the room 100%? I don’t think so

Solution 3 would be an option or maybe solution 4

The problem is the guest WC is a very small rectangle

On the right in the corner is the toilet and on the left directly opposite is the sink. The wall where the door is is always next to the toilet and sink

But then I don’t understand the developer. So on the living side, what does the baseboard have to do with the tiles in the bathroom?

Regarding your questions: I understand the respect for tiling yourself. I did a very small area in the utility room myself. It works, especially with a leveling system. The grout color is not the problem if you use the same grout (you can inquire about that). It’s more about mixing the consistency correctly. You always use too much water at the beginning. But cutting small pieces cleanly, which would be necessary for example at the door frame, does require quite some practice.

Regarding the toilet on the same wall. Some people only tile the back wall in the area around the toilet and sink. So about 30 to 50 cm. The rest of the wall remains free (except for the baseboard).

I don't understand the developer then. So on the living side, what does the baseboard there have to do with the tiles in the bathroom?

Sorry, I expressed myself incorrectly. In the living area, they leave out the last baseboard to the left and right of the door frame, and then after installation of the door we have to mount the last baseboard up to the door frame ourselves. Doing the wall tiles ourselves is not an option for me. Our solutions would either be to live with the gap, tile up to the ceiling, or leave out the tiles on the door side. The last option would be to have the door in the guest bathroom and hallway (where the problems occur) installed immediately and tape off the door frames during painting (if the developer even agrees to that).

The column is, however, in tile thickness plus adhesive ... that should have been planned.
Please provide the floor plan of the guest WC.

This is the floor plan of the guest WC

I would only tile the wall on the right up to half height and on the left about one tile width, approximately 40-60 cm into the room.. also half-high And then there should be no problem with the door frame. Hopefully, the door opens outward.