The question was, how much are YOU comfortable keeping in your prop account, not how much the regulations or risk managers require.
You want to keep as much as you can to give you all the bp you can use, but what I'm asking is, at what point do you start to worry about your funds' exposure to your firm as a whole.
Especially if you start to branch out from daytrading into keeping positions overnight, you could probably still get alot more leverage at your prop firm vs retail, but again, putting all eggs in one basket is probably not good idea?
How about answer this question: how many full time prop traders have multiple trading accounts with other retail firms?