Ok so you keep a 30 buy in roll to play at certain stakes. Then you "go on a bad run" and lose 7, you are no longer bankrolled for that level so you move down and try to rebuild? Also 7-10 buyins downswings are NOT downswings. If you lose that many buyins at a certain level (especially in 2-3 days like some said) you really need to rethink your game, you probably lack the skill to play at that level.
I personally play at 200 NL, cashing out my profits every 2 weeks and leaving 6-7 buy-ins as a "bankroll". Some times just before I cashout when my "bankroll" (I mean the money in the site cause cashouts go in the bank) is at its highest, I play a little 400 NL too. If I want to move up to 400 permanently I will not cash out one time and leave sth like 3K at the site.

There's a diffirence in the BR you need to start at a level and the BR you need to play at "your level". I CANT lose 10 buy-ins at 200 NL unless I play drunk or sth. Aces or rilla CANT lose 10 buy-ins at their respective levels. When I started (with 32 bucks from a freeroll) I followed STRICT BR management rules. I played $3 sngs and then $10 NL, then 25 NL when I had $500 and so on. At 200 NL I decided to stop moving up and see what money I can average there. Had I never cashed out I would have a BR of about $10.000 at the site. But hey I like they money I've won in my hands not a number on the screen that I cant touch cause its my "bankroll" .

b cool all.