The 5-card Charlie rule definately helps the player, and when i was shooting Celeb BJ i think i knew many of the basic variations to BS, but can't seem to recall now... basically it involves hitting on many 4-card totals you would normally stand on, like certain 17s and all soft totals. Obviously knowing the count enters in to these calculations as well, and as Ken said, things can get kinda complex rather than there being a hard-and-fast rule.
The Joker was much more interesting, as often the use of this option had less to do with improving your OWN hand & more to do with screwing up someone ELSE's... just like in standard tournament blackjack, there are many times when you are taking the low on a competitor who has a large bet out...even if you were dealt a crappy hand here, if you receive the joker it would be in your best interest to try and ruin the blackjack or hard 19/20 of your opponent even if taking this card still leaves you with a bad total...for this reason its almost impossible to calculate the true value of these Jokers, since they have less to do with your mathematical edge over the house & more to do with the much more subjective realm of pure tournament strategy.
As for how many times i've been accosted in a casino -- been shown the door more than once, but never gotten into a fight over it -- though admittedly from watching me on TV i can understand how that may be a hard fact to believe!
