If I use a prime & paint that is interlocked do I need to also prime?

I have stripped wallpaper and found that the walls have been previously painted. I have had to repair parts of the wall with filler. I want to repaper with lining paper and then repaint using matt emulsion. What is the best preparation before I put on the lining paper? Should

We managed to have a cooking accident in the kitchen and oil splattered onto our freshly painted walls and ceilings. It has come off the walls but there are marks on the ceiling. I tried in one area to clean and paint started to come off the ceiling. Is there

What color do I paint the inside of a exterior door? The trim around the door is white. Can I paint it dark?