HI Rachel

thank you for participating here

actually I use Capture One when I am tethered to the computer for shooting - basically I use Capture one primarily for actual image capture.

I do use Lightroom for processing my RAW files

1 There are a number of similarities between Capture One and Lightroom and usage preference partially comes down to what you are use to but I have personally experience that Capture is much better for receiving files quickly when I am shooting - where as I prefer the interface for processing files with Lightroom

2 Yes there is a certain amount of compatibility issue with software and actual camera gear you use but I find that the major software like Capture One and Lightroom are fairly universal in working with a wide range of gear

3 I guess I touched on this in the previous question - Capture One and Lightroom are both good on compatibility