I am putting recessed mains halogen lights in my kitchen. These will be
in a ceiling that I won't be able to access from above, once in place
(it is a single story extenstion, with a pitched roof, but no room for
a loft hatch). I am using crimped connections as a result of this
inaccessbility. I have a couple of questions that I hope this group can
assist with.

1. I am putting in a completely new plasterboard ceiling. As I put this
in I will also be adding insulation. How critical is it to leave a gap
around where the lights will be. My intention was to have the cable
lying between the joist. Then cut a hole in the ceiling after
plastering and pull the cable through for connection. At the same time
making a small hole in insulation. Presumeably, neither fibreglass or
rockwool are flammable so I figured this would be ok. I have heard
about using plant pots, but these will be tricky to get in place whilst
putting the ceiling in place. What are the pros/cons of this approach?

2. In conditions of heavy wind and rain, I get a few small leaks, but
less than a egg cup full. This appears to be due to the roof lining
which needs replacement. Unfortunately, due to time constraints and the
weather, I am only intending to lift the tiles and replace this next
year. Is there anything I can do to prevent this damaging the newly
plastered ceiling. The previous ceiling seemed to have withstood this
fairly well.

Thanks, Tim