2. Theres a sticky on this thread.Been looking on doin same to mine but cant find any for a decent price.

4. Universal kit should work.Need to do a bit of drilling i believe.

Interior light prob is probably dodgy pin switch on drivers side if it works when u switch it normally.
Also i havent got a warning tone when my lights are on anyway, not sure bout everyone else.

Havent got answers for the others,soz.