i currently use 13 Accounts.

PVP is currently on going thing, trying to get at least 5 or 6 with OGB to be able to pvp effectively. Ratting with all 13 at once is really not an issue - however not as effective.

I primarily rat with only 4 toons to get "decent" isk per hour.

For the most part i do heavy production, so i use my team primarily to mine 10 Miners 1 Booster 1 Hauler, 1 Scout/Defense.

4 Accounts are doubled up with High-sec Freighter/Trader toons so i can High-sec trade while living in nullsec.