Patching and Plastering - 2 part question on Plaster Ceilings with Cement backer stuff

I am getting ready to gut my kitchen and redo the entire room, and hoping to not have to tear down the ceiling to make it look decent.
While waiting for the new cabinets to arrive I decided to redo the adjacent bathroom.
Tonight I took down the wall paper from the ceiling (is this as odd as I think it is?) only to find an 1/8" layer of plaster cracked and falling away from the grey backer board it was spread over. The backer board looks and feels like cement with a semi-circle swirl pattern in it (think rough sidewalks). What is my best bet for repairing this ceiling? Which leads me to another question about finishing a ceiling, but thats another thread.

The house was built in 1956 and I live in Minnesota. The entire house was remodelled by a "professional" designer in the mid '70s, but I got a great price on the house because of the decorating.

Ok, so that is my first question... how to fix the bathroom ceiling. The room is only about 7'7" by 4' and it only has a toilet and sink, no shower. My thought was to scrape off as much loose plaster as possible and frame the ceiling down 1.5" with some 2x2 stock and put drywall up.
The other concern I have with the ceiling is that there are a few cracks running through the cement backer board, worth concern?


Second question (yes its a quick one):
I am assuming the kitchen celing is the same structure as the bathroom sink, so what are the best and least dusty ways to cut holes for recessed lights in this material?
I have cut into plaster with wood lathe many times, but not into this concrete stuff.



Sorry for being long winded, and thank you in advance for your suggestions.
-Pete

Here are some pictures of the ceiling in case it helps:
Ceiling 1 (http://home.comcast.net/~dripdrown/ceiling1.jpg)
Ceiling 2 (http://home.comcast.net/~dripdrown/ceiling2.jpg)
Ceiling 3 (http://home.comcast.net/~dripdrown/ceiling3.jpg)

Thanks again.

sounds like a good idea to fir out the ceiling and the easiest too unless you can go right over it with the sheetrock after removing the loose stuf and maybe bringing the low spots flush if you want. To cut the holes in the ceiling here is a tool

http://www.brite-lite.com/Products/demo.html.

You can make your own I am sure someone will post with there own homemade dustcollector. There are any number of ways. Right now I need to finish watching Malcom in the middle and That 70's show

A "cheap" 5" hole saw will not make much dust with a plastic container or aluminum pan between it and the drill.

Won't the cement backer board eat up the normal hole saws and that bright lite tool?
I have a dremel, but have never had good luck with the circle attachment for it.

Are you sure that is cement. There is a carbide tip 1/4" for the dremel but I don't know if it will work,maybe a roto zip it has more power or maybe the tool in the link has a tip that will handle it The hole saws don't cost too much. You may be able to get a few holes out of one, then a new one. See if you can get an answer in the electrical forum. I'm sure there is someone who has had to deal with it. you may want to find the easiest way to run the wires while your at it. The kitchen may be a different story than the bathroom if you will be spending a lot of time doing wiring.

Think plaster. In a house that age it is probably gypsum plaster over gypsum lath. The successor system to gypsum plaster over wood lath. This is a very good system. Do you know something that the pictures don't show that make you think it is cement board? I think you could have a new smooth or textured plaster finish applied if you can get all the existing finish off. I think that is a little too specialized for you so if you want new drywall go right over what's there. Use long enough screws. Don't align a joint in the drywall with the crack in the ceiling