On the flicker issue, I don't know for sure without trying the GH2, but I would imagine that light flicker will be a problem when shooting 24p. Most low shutter speeds are fine under 25p and the majority of lights, unless of course you're shooting a monitor, then you need to match.
Shooting at 1/50 24p should be fine, but it's not always safe to assume
Shooting at 1/50 24p should be fine, but it's not always safe to assume