I too have been looking for a solution. I mostly shoot corporate and commercial work but also freelance for several national news organizations. I have retired my P2 cameras and started using the FS7 to shoot the news gigs.
Sony's FE PZ 28-135mm f/4 G OSS lens, while affordable, doesn't come close to what I need for shooting news. With this camera I need 17mm or less on the wide end (for candidates working the rope line) and 250mm on the tele end (for H&S shots of the candidate at the podium from the media riser). So that is roughly a 14x lens. f/4.0 is okay but not what I am used to from my Fujinon lenses.
What this means, for now, is that I am ALWAYS carrying two lenses with me and hot swapping them between the rope line and media riser locations. I have only used the FS7 this way a couple times so far this year. I may be going back to the lesser but more versatility lensed Panasonic P2 camera.
1) I can live without a power zoom as long as the zoom ring mechanics are smooth
2) The zoom must be parfocal
3) The zoom must be constant aperture (thought I could experiment with auto iris)
4) B4 adapter won't work for me - wide angle is completely lost, some adapters vignette and all adapters plus x2 introduce too much CA
5) Yes, I know each one of my Fujinon lenses cost more than my FS7. Nuff said.