If it is highly probable that paints and glues contain impure substances, and it is unknown whether they have undergone a transformation (istihalah) or not, and it is not known with certainty whether a specific product contains these materials, is it prohibited to use it? And if a wall or door is painted with a paint containing an impure substance and it comes into contact with water without the paint being affected, does whatever touches it become impure, or does it take the ruling of dry impurity that does not render other things impure?

It is clear from your previous questions that you suffer greatly from waswasah (obsessive whispering/doubts). Therefore, you must seek treatment for these waswasah by ignoring them and not paying attention to them. We also advise you against asking hypothetical questions. The default status of paints is purity, and nothing deviates from this except with certainty. So, if you are not certain of the presence of an impure substance in them, then they are pure and permissible to use, especially if the doubtful substance is alcohol. For indeed, if wine solidifies and its intoxicating property vanishes, it becomes pure, and dyers use it.