No, but it does have to be smooth, preferably sanded.
I do not think that is a good idea.The rubber flooring should be removed and then new ceramic flooring should be laid on.
Soak them in water 3-4 days, then it can be removed with a metal spatula.
From my experience, It is recommended to remove as much existing glue as possible then apply a sealer just for this purpose available at your local hardware store or tile shop. This creates a positive bond and will ensure a long lasting tile installation. Take note that if your glue down flooring is glued down well and is not loose or coming up they make a couple of products that prep this flooring which allows tile installation to be applied right on top. I have not personally used this as I am an old school type of installer however I hear that these products work well. StraferX
Yes
How can you recycle ceramic tile you are having removed from your house? I AM SOOO MOT SURE IF THIS WAZZZ REALLY YOUR QUESTION, BUT I'LL KEPP MY FiNGURES CROSSED AND I REALLY DO HOPE IT DOES. 
form_title= Oak Flooring form_header= Give your home a face lift with oak flooring! What is the square footage of the area?*= _ [50] Do you need old flooring removed?*= () Yes () No How many rooms will have the oak flooring?*= {1, 2, 3, 4, 5, More than 5}
Goo Gone.
Event Flooring is portable, easy to install and can be removed quickly. It is available in many varieties such as cherry wood and can serve as an instant dance floor.
What kind of acid and what kind of flooring is very important to this !
Wait till it sets then pull it firmly off.
Rub it with Goof Off and it will soften enough to be removed.
form_title=Install Vinyl flooring form_header=This type of flooring is stain resistant, holds up well to normal wear and tear. What is the square footage you would like in vinal flooring?=_ Do you have another type of flooring already on that needs to be removed?= () Yes () No Do you want a cost effective plan or genuine vinal?= () Cost-Effective () Genuine