Since you didn't specify, as there are many products on the Elgato website, I would guess you are talking about the HD60 or s? I couldn't say for sure as other reviewers were having slight problems just with using external USB headsets. Using this mic and a headset plugged into the mic, might work best.
it depends on your computer setup and how old it is. If it doesn't work for your intended purpose, return it.
If you are running Windows 10 with the Game Capture HD60 Pro, you should have no problems.
If you are trying to use it with the Elgato dock? Again, shouldn't have any problems.
Read the requirements on their website.