Q about elevator balance

I removed the elevator from the horizontal stab the other day for an
inspection of the pivot pins/bushes. The elevator has got a bunch of
weights attached to it, extending forward of the pivot location.

1. This is a humble question: does the elevator weight have a purpose
other than balance? Does it have any connection with flutter, or is
flutter more a function of excessive control mechanism backlash combined
with velocity?

2. For a serialized production glider, is the control surface balance
weight amount the same for each glider, or is it tuned for each
individual surface, making surfaces non-interchangeable between gliders?

I'm just trying to learn something on the topics of balance & flutter.

Ken
LAK-12