Do molars need to make direct contact on top of each other? feel bottom molars moved in too much and also increased wear into enamel due to pressures

Clenching n grinding: Sounds like you clench and grind your teeth. Your teeth r supposed to contact the opposing teeth and if you are aware of wear spots and teeth moving it's from clenching n grinding. The fact they moved could also mean you have some bone loss. So you need to have your dentist or a periodontist (gum specialist) check for bone loss. Also have your dentist make you an occlusal guard for headachetmj.

No they do not....: Lower molars work best when they are situated slightly in toward the tongue relative to the upper molars.

Yes: The molars should contact. If the lower molars are in too much toward the tongue it can cause abnormal forces on the molars and excessive wear can occur.

Occlusion: While teeth are meant to occlude with each other and it would be nice if everyone had an 'ideal' occlusion (bite), that seldom exists, even after orthodontic treatment. There is always wear and tear on the teeth. Two issues can cause excessive wear- malpositioned (crooked) teeth and habits such as bruxism. See your dentist to determine what if anything should\can be done for you.

Guidelines: There are specific guidelines that allow dentists to gage the correctness of your occlusion. Teeth work best when the teeth and jaws relate to each other in a specific fashion. The better they fit, the better they function, the better they look the easier to care for, the most long-lasting. Ask your dentist to review your occlusion and discuss with you any disharmonies. Remedies are available.