Q1. I can't find any instruction that states that these will be withdran and scrapped. Just suppose they're serviceable......!
Q2. If they were fully serviceable they wouldn't be scrapped
Q2. There isn't a mark, so far as I am aware that indicates perfectly serviceable, but scrap..................
Q3. Scrap rifles guillotined/torched or sold off as such.
Don't know.
ZF rifles can have training value. Convert to DP. Been done since the tear dot!

Bit of advice. Don't invade Russiaicon and don''t use a DP or ZF marked rifle