Achievements would be great. My only question is what happens after you get the achievement and then trade with that character.
You see I have no problem with some achievement or flag for a self-found character... but 99% of the self-found claimers with great gear are full of it.
You would need to start a new character and then that character must rise through the levels and get the achievements, however if you then trade after you get the achievement..maybe you loose them and have to start over(but only if you trade with that particular character).
You can call the achievement "McGuyver" - "You have mastered foraging, you make use of the elements and the environment to craft your own gear."
The idea is the same as with Hardcore. You play through the game and get the achievement, so you get your badge of honor. Then after that you can still change your mind and say, hey I'm gonna buy some gems from AH because they are just a pain in the a$$ to get SF. You won't lose the achievement, you already earned your badge.
What could be done is that you do lose the profile tag however. So the player has the choice about what he wants to do with the character rather than being locked in a ruleset.
For some people reaching lvl 60 by doing SF is enough recognition. For some people plvl 100 SF might be what they're striving for.
Some people might want to get the badge of honor and then not lose it when they do decide to trade.
The problem I have with the whole SF thing is that there are too many opinions what a SF mode should be.
What we need is a flexible system to give as much people as possible what they want, without having an impact on other players or game mechanics.