Re: Cracked and Stained Ceiling Tiles
If it were me I think I'd live with the cracks and just seal and stain the ceiling. Removing an acoustic tiled ceiling is a pain in the buns, messy, and could open up a whole new can of worms you are not willing or able to deal with.
Stay away from paint/primer combos, they are expensive and not worth a dime. Use the Zinsser red label primer, it is a pigmented shellac specifically for stain sealing. You may have to use several coats depending on how porous the ceiling and severe the stains are.
The way to know how much stain blocker to apply is to watch the stain, you apply another coat until it no longer bleeds. I would recommend applying the stain blocker to the entire ceiling, then continue spot priming the stubborn areas, followed by another coat across the entire ceiling. Doing it this way will give you a good, even base to apply your top coat to. When the stains are fully sealed in you can top coat with your paint of choice (two coats for good, full coverage ).
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!