Looks like a great photo opportunity, and I do understand your problem, I also shoot Nikon with the SB800
Well lets say I have taken a few shots of pole dancers (hmmm) watch her go through the dance/act while warming up at least once so you get a feel for what she is going to do in the act/dance so you know where to be to get the best shoots.
I usually broke mine down into to groups and each would have there own effect. Group one is the dance studio/Bar look that you have here. The image is softer and the background is lighted and drifts off to out of focus but you can still see the furniture walls, flowers and people also looks like you turned up the ISO Speed, although that grain just might be the room light.. You can easily improve on this with a few steps like camera in manual mode, Focus set to center only, white balance set to 6000 or so, shutter at 60 and the fstop will vary a little I like f4-5.6.. You can take the 800 off the camera and move it to the side via a cable or remote mode in manual mode not TTL and the whole picture will look better. If you add a Softbox or defuse the flash with the defuser that comes with the 800 and angel the head toward the ceiling and even try a few with the main flash on as well.
The second type is a studio style the best of both unless you want the (bar) crowd in the picture for effect of the gauker's staring at the dancer. House lights down, Camera in manual mode, Focus set to center only, WB @ 6000, SS@ 125, f4-5.6 Professional strobes and Softboxes 2-3 left right and hair light or if background accent light on a near by wall or backdrop use a Gel for some color when out of focus it still looks great. The effect is great and the shot will be very clear and stop action is a little better at SS125...
Just a couple of things I did to improve my shots for this type of shoot. Have fun !!