You can use the small monitor for focusing since the image can be magnified, but you can only magnify it in the center. So if you're setting the focus and recording it works fine, if you have to change focus while recording you'd be much better off with a better monitor.
There is a focus tool (with small squares) which is very helpful and can be used with the monitor.
It always comes with an AB-mount but you can either get an AB>V-lock adapter or just exchange it to a V-mount. I changed mine to a V-mount and it works great. It's easy to change it.
No, you have to record it to P2. I prefer shooting in 4K/UHD since I've noticed that the 2K footage (no crop) is more prone to have colour moiré in it.
Thanks. I had assumes it would need a swap out of the battery mount but a shame that it isn't offered in both configs.