Is this mold under the tile? There was a leak. The floor is not weak when standing on it. Does the subfloor need to be removed? Or would corcobium spray do the job? And how to remove tile glue? Thanks!!
I probably wouldn't worry about the mold. Even if it is mold once you put your new floor on top of it (depending on floor type) the mold is embedded and won't cause problems. Mold is almost everywhere in small quantities. I'd expect once your flooring goes down that this would be equivalent or a smaller issues than the mold that likely coats the inside of all of your plumbing pipes.
If the floor is stable I'd just ensure the floor was dry before doing whatever you are going to do on top.
You probably just want a heavy duty floor scraping tool to remove the adhesive.