Is the Islam of one who dissimulates, or does not know of the disbelief of polytheists, Jews, and Christians, or relies on humans to fulfill his needs instead of God, or mocks the Arabic language, or doubts the existence of God while having some misgivings, invalidated?

Your question stems from obsessions about apostasy, and the cure for it is to ignore them, stop preoccupation with them, and not surrender to them, along with consulting psychiatrists. Attempting to cure this by seeking fatwas is not a solution; rather, it will worsen the situation. The default is that your Islam remains valid.