TechGal, I would say the organization would depend on what you are interviewing for. It's been touched on briefly in here on page 2 of this thread, but it deserves repeating again - tailoring your resume when you're seeking a specific position is definitely a big help! I would say, make it modular. Put together a series of "clusters" of work - either by venue type or by position. If you're shopping jobs where diversity of skills is a plus, then use the "position" modules, with the module for the job you're actually shopping on top.
So, if you're shopping an LX position, your LD/ME stuff is on top. If you're shopping Corporate floor management, then either corporate work goes on top or floor management work goes on top, depending on who will be viewing your res. If you don't know or you're cattle calling, then sort it by whatever you feel makes the best impression. In this market research is critical. Know the company you're shopping for jobs. Know the preferences of the hiring folks if you can. Thank them afterwards. A good stage manager will generally exhibit versatility. A modular, customizable resume is merely an extension of this strength.
As for your current gig, if it's an AGMA gig then a union mention should cover any confusion. If not, then Stage Manager (Independent Contractor) is simple and clear.