Could TMJ cause hearing loss? Could TMJ cause lightheadness?

No to hearing loss. Tmj disorders or temporomandibular disorders do not cause loss of hearing. It is an umbrella term encompassing several pain disorders of the face and jaw; most common is musculoskeletal pain. Light headedness is not an uncommon symptom in temporomandibular disorders. Consult your dentist (or an orofacial pain dentist) and your primary physician. If hearing loss is sudden and constant, ent.
YES and NO. Symptoms of tmj/tmd can include hearing problems, dizziness (equilibrium/balance difficulties,) and other ear related problems. But tmd can also be wrongly diagnosed if the ear/ears are the source of the problem. I would first see an ENT doctor to rule out ear/inner ear infection, etc.
Unlikely. The TMJ has to be very severe where there is erosion into the middle ear canal. But usually the TMJ is treated before this even happens. So it is very unlikely that TMJ can cause hearing loss. There are many causes for lightheadedness and TMJ is very low on the list.
Yes. Yes. TMJ problrms can cause subjective hearing loss. Not tru hearing loss. And can also cause lightheadedness.