Remove of airdropped merits will make old Senior Members, Hero Members and Legendary members feel paranoid, like what theymos said on misuse or too serious use of trust system months ago. Good old users can rank up again, even their airdropped merits removed and they will be deranked. They definitely don't have issue to move up again, just need a little bit time. Nevertheless, once again, I don't think airdropped merits will be removed because of probably paraniods.
Thinking about it how about "rolling merit"
Instead of:
Brand new: 0
Newbie: 0
Jr Member: 1
Member: 10
Full Member: 100
Sr. Member: 250
Hero Member: 500
Legendary: 1000
You need:
Brand new: Same
Newbie: Same
Jr Member: Same
Member: 10 but must get at least 1 every month or you drop to Jr. Member
Full Member: 75 but must get 5 every month on average per rolling 6 months or you drop to Member
Sr. Member: 150 but must but must get 7 every month on average per rolling 6 months or you drop to Full Memeber
Hero Member: 450 but must get 8 every month on average per rolling 6 months or you drop to Full Memeber
Legendary: 750 but must get 10 every month on average per rolling 6 months or you drop to Full Memeber
This way if you are off the forum for a bit due to work, life stuff, etc you are not dropped straight down to a lower member tank for months, BUT if have status you have to work to keep it with good posts.
And, even if you are legendary and you have an issue and have to leave for a year, in 6 months back of good posts your status is back
-Dave