I'm primarily a video shooter so all my lenses are manual and it took me a while to get used to using them for photography and it pretty much just took a lot of practice.

A few tips: Shoot at higher shutters peeds. I normally have my shutter on at least 80 if I'm photographing anything with a lot of movement. I often crank it a lot higher.
Forget about the low apertures. You're Voigtlander's f0.95 is great if you have a static subject, but has such razor thin depth of field you can forget about getting any movement with it. As a general rule, the more you close up your aperture the easier it will be to keep focus. If you're not already doing it, shoot RAW for images. It's a lot easier to sharpen up (slightly) soft images and gives you a lot more tweaking room in post.

But going back to the first thing I said, practice. If you're not comfortable with manual focusing, don't do it at a wedding, you're putting someone's big day at risk. Suck it up and lug the Nikon along with you.

I usually set up M like the Video mode, except with varying shutter speeds, different aspect ratio, everything manual; in burst mode... And along the lines of what stonebat writes above. Recently though I've started to set everything up in advance (exposure like I want it) and just wait for things to unfold..

Set up for small jpegs along with raw for easy preview.

I have those same lenses, but I usually defer to the leica pana 25mm in single af mode for stills. The little camera with sharp, fast af glass can do a good job. Actually I set in AF+manual, so I can attempt to dial it by eye. It's not the best stills camera I've used, but a great one nonetheless. That new 12-35mm sounds perfect for this.

@htinla Thanks for your extremely valid point! :)

It's not paid work no, its for friends... I've shot about 6 weddings over the last 5 years or so, all stills. I was into stills years before enjoying dabbling with video so its really stills that are the things i know i can do ok. It's just since getting into video i've found it very hard to ever choose NOT to try video... it's going to take me some time to rediscover a drive to want to take more stills.

I would prioritise stills over video i think, though i've not thought it through properly yet. I've done a lot of reception videos lately, where you can just get nice moments as people have a good time. This is probably the way i'd play it.. stills for the ceremony, video for later parts of the reception and little bits in between.

I asked on this thread about manual lenses in particular as obviously that's what i've mostly got on my GH2, 14-140mm aside. My query was more it just seemed to me that the GH2 was buggy when working with manual lenses in stills mode... just from the fact that i took shots and they just wouldn't have a good exposure. As i said, in the end i had to manually select an ISO to try and get an exposure that was right. I'm sure its the contactless lenses that are perhaps confusing it a little.

Totally right about what kit's best for wedding shots where the moment is fleeting.. I've absolutely felt 100% comfortable shooting the few wedding stills i've done with my D3 over the years.. its just pretty much bulletproof, and fast!

I know that I'm certainly not up for juggling the two in any one moment, and obviously both will likely suffer from such an attempt. I'll have to have a real long think about it, as well as more stills testing with the GH2 and my lenses to see if it can gell with me in stills mode as much as it does in video!

Thanks again though!!

Using manual lenses for "fleeting moments" is definately possible, just not recommended if you feel insecure with it.. With plenty of experience on a single lens, finding focus is; if not as fast as AF then fast enough and accurate enough to get the shot. I mean, it was done for so many years before we even heard of AF. Especially in a crowd of people it can be a big advantage to shoot manual (even if it´s not manual glass) because you can set the focus in the right areas and not have to worry about it, whereas AF might fuck up a great shot because it chooses to set the wrong area in focus...

I recommend going fully manual if shooting with the gh2. Do it a lot, and it will sit in your backbone. (remember, you can set up the settings for your particular environment and be about right when you want to actually start shooting - I recently did this on an analogue camera without a light meter; measured before and set up the cam / did small adjustments when I thought there was a light change and my hunch was suprisingly correct for 72 frames) Then use auto features / lenses if the situation so requires.

Shooting both video and stills simultaneously for events is a no go, absolutely. Unless you can set up a static "objective" camera and shoot stills without having to think about the other camera. For "sight seeing" or visual reverie (where success is irrelevant of documentation properties) it works, np.

@jimtreats Shutter priority is useless with manual lenses since the camera can't auto adjust the aperture. According to the user manual, Constant Preview (WYSIWYG mode) is only available in manual mode. Would've been nice if it were available in aperture priority mode too. Oh well.