Is what I experience of whisperings concerning istinja' (washing after defecating or urinating), wudu' (ablution), ensuring purity, and the articulation points of letters in prayer and the Quran correct?

It is recommended to disregard obsessive thoughts and not to dwell on them. The criterion for sufficient purification (istinja') with water is that the area returns to its original rough state. The default ruling for splashed water is purity, unless it changes due to impurity. If a person is certain that impure splashes have touched the body, scrubbing is not required to remove them. Some scholars even excuse minor impurities altogether. A person afflicted with obsessive thoughts is not obligated to strain, clear their throat, walk, or do anything else after urinating; rather, this is a form of obsessive thought and innovation (bid'ah). Doubts about water entering the front private parts or doubts about the release of gas or wind should be ignored, and ablution is not nullified merely by such doubts. A person afflicted with obsessive thoughts is not required to inspect themselves for any discharge before every prayer; rather, it suffices to act upon the default assumption, which is that nothing has exited unless there is certainty to the contrary. When in doubt about the type of discharge, it can be considered pure vaginal moisture for someone afflicted with obsessive thoughts. According to the Maliki school and Ibn Taymiyyah, it is not a condition for the reciter in prayer to hear themselves; rather, it is sufficient to pronounce the letters from their proper articulation points and to move the tongue and lips. One must distract themselves from obsessive thoughts and seek Allah's help.