The E30 and FL50R sure made the flash part of the work easy enough. I just made sure I had the minimum sync speed set down low enough in that menu option, in this case I set it down to 1/30 second to make sure the metering system had a low enough speed to mix the fill based on the ambient light levels. I manually set and adjusted the ISO setting, but could have easily just left it on auto with a sensible range and that would have worked fine, too.
I do with I had had the 12-60. I wound up using the little 14-42 kit lens when the 50mm setting of the 50-200 was still too long. The 14-42 did OK enough though.