I'm assuming that you don't have many casinos near you, so you're spending a lot of time on sessions at the few places you have. Sound about right? I also play with a somewhat obscene spread (1-60 at times), but I understand that this can only work under certain circumstances. If you spread heavy or even just play a mild game for any length of time, the casino will observe you, and you will be detected. Most likely your problems have come as a result of playing for too long with an obvious card counting strategy. Especially if you are winning, you will be under scrutiny. Also, depending on the particular casino's "choke point," you may be backed off even if you're just winning ($12K is a lot for many smaller places) and they simply don't know why.
For the type of team play that you're suggesting to work, you need to implement a very large spread. For example, if you're flat-betting $10 a hand, your BP needs to betting much larger than $500 to make it profitable and you'll need a very large bankroll to lower your risk. And as noted by other people more knowledgeable than myself, you will not be able to pull this off for any length of time at one casino.
If you want to increase your profits and you feel that you can bet up to $500 a hand, I have a suggestion for you. At that limit, you should be able to afford airfare for you and your partner to Vegas and play quarters for about a week. You can spread wildly, playing individually for 45 minute sessions, and get great playable games all over town. Your EV will (theoretically) pay for the trip. The risk of being backed off as an unknown player at these limits, playing short sessions, is not very high, although a max bet of $400 (or 2x$250/300) might be less conspicuous. This type of team play (every man for himself) will decrease your variance and double your win-rate (since you're playing twice the amount of hands).