What I see every now and then are translated variable labels. Since it takes an eternity before a correction is accepted by the ever so slow community decision process (everyone is busy with other things), the irritation and annoyance builds up whenever a new site is set up with again the same stupid translated variables that break functionality of the string.
The best way to approach this problem is by preventing it. I therefore suggest here that in the translated string only unchanged variables are accepted. Sometimes a translator or in special cases you want to remove the variable. I therefore suggest that only changed variables and not the removal of them is inhibited at data entry level.