I have read with interest the threads on rifle weight and several opined that balance was more important than weight. Could those who have thoughts on this matter, please explain further. Does it mean weight forward (but from what reference point--the forward action screw, or should the balance point be defined as measured from the trigger?)? Old Jack O'Connor thought the sun rose and set on the M70 Featherweight--does this rifle define perfect balance?

The center of gravity or balance point is the location ,normally in front of the trigger where you can balance the gun. It is not the weight but the weight distribution. If you add significant weight to a gun to reduce recoil it should be added in both the buttstock and forend to maintain proper balance.

Only you can define balance with regards to a rifle. Its kinda like a baseball bat or a fishing rod. There may be a rack of them that appear identical but one will feel "better" than the others.
The balance is the point where, if you are holding the rifle with one hand, hanging at your side, the rifle doesn't tip forward nor backward. Often it is around the trigger or in front of the trigger. I like my balance point to be forward of the trigger because I like a little weight forward of middle. It seems to help me on moving shots and offhanded shots.
A well balanced rifle is more important than actual weight because it lends itself to being carried several different ways so you can trade off positions of carry and rest some of your muscles.

I tend to like muzzle heavy for rifle and pistol both. Seems to hold a lot steadier. Also comfortable to hold in the hand on long walks out west. I'm more comfortable with the rifle in my hands than over a shoulder although I've met a few who carry over the shoulder and can still get into action pretty quick.

The informal method is to cup your hand under the front action screw with the rifle horizontal at your side.

The formal way is to shoulder the rifle and fire at a moving target, as you would with a shotgun.

There are a lot of factors that effect balance, and most of it depends on individual preferences.