I understand teeth shouldn't be clenching, although I read somewhere that teeth should naturally be in contact when the tongue is on the palate. When I put my tongue on the roof of my mouth, my lower and higher jaw don't touch. So, I need to constantly posture my teeth to be lightly in contact.
Should they naturally come together and stay together when I put my tongue on my palate?
Yes, lightly. In growing children with overjet this is a very important step because it signals to the lower arch to grow forward and sideways to match the upper arch. Adults benefit from it as well because teeth in light contact give support to the maxilla and insure the arches stay matching.
my story: http://www.aljabri.com/blog/my-story/