Depending on the flash duration, you might run into issues with fast shutter speeds with very fast flashes.
As long as the shutter duration is longer than the duration of the flash, it shouldn't be a problem. Some flash or strobe units have shorter durations at lower power so it might be advantageous to use a lower power setting. As for reducing DOF, using a long lens with a wide aperture will help.
“We are buried beneath the weight of information, which is being confused with knowledge; quantity is being confused with abundance and wealth with happiness.
We are monkeys with money and guns.”