John, thanks for the advice and the words of encouragement. Recently I've been falling under the siren sound of 4K and UHD video, while in fact I'm nowhere near ready to use that technology effectively. My lightly used GH2 just took on a new luster...
Lens-wise, I don't have the 12-35 and it's not in the short-term plan. I do have the original Panny 14-45 kit lens, which used to have a pretty good reputation for stills. Do you see any significant disadvantages for using that lens so long as I'm not zooming during recording?
Regarding sound, thanks for reinforcing some lessons I've been getting online. I do have an external mic for the GH2 (Rode Videomic), along with an audio recorder (Zoom H2N) and wireless lapel mic (low-end Audio-Technica). Some familiarity with Audacity, curiosity about PluralEyes. Primary editing software is iMovie 10, secondary Adobe Premiere Elements, long-term interest in Final Cut Pro X. Total novice on lighting; time to gain some knowledge.
Thanks again for sharing your expertise; it's much appreciated.