The fixture comes without light bulbs. It has a conventional screw in type socket. The type of bulb you buy is up to you. It can be daylight or soft white or whatever.
It can be installed to an existing housing can.
The instruction guide is fixed and will be available in 48 hours.
Compatible with any insulated and non-insulated ceiling 6 in. housing.
No it's not.
It's not air tight and you can use dimmable LED trims.
Yes it can be used.