I asked some questions like a week ago and you guys were foolish enough to reply with good information, so I am back to ask more..

Since I am now doing remodels and having to take over some of the painting jobs.. Before this I worked strictly new construction so some of these things over old stuff is new to me..
Working on the small remodel job now that I was actually asking the paint questions for. Ceiling right now is currently textured with a slap brush that has been painted, they want a new textured ceiling(knockdown). Lights got moved, some of the ceiling wasn’t done so great so they wanted all new.. I originally quoted to just put 1/4 new drywall over it to start fresh.
Well I guess their budget got way blown on other parts and they are trying to do any grunt work they can to save money. Since they don't feel comfortable laying he new drywall on the ceiling they are going to try and remove the texture..
So here is my question, they tried scraping it and they are beating up the paper pretty bad. Tearing I guess the top layer and making it all fuzzy. They also said it took forever to do even a small area. I stopped by to look at it today and in a small area next to theirs I just took one of my rasps and knocked it all down. It isn't smooth but a texture is going over this.. It went very quickly though.
I told them I would try to find out if they could just do this so they could save the money in having me hang new.
So, can I just have them do this and get it somewhat smooth with no ridges and then just prime with GARDZ and texture over it? It is stuck down very well. And will GARDZ fix up that area they beat up enough so I won't have any problems? The area isn't all the way through the paper, but as he scrapped off layers of the paper kept coming off as he was trying to get it smooth..
I have done about a million textured ceiling, but every single one was new construction and the drywall was new..Never done this before with having to remove one.
Thanks for any advice.