That helps explain why Rosetta doesn't work, it is no longer supported.
Ever since Lion Rosetta has been dropped, all software that runs on Macs now has to be written forn the newer OS X.
What that means is many people, like yourself, have older software that was trusted and did the job as designed.
Much of it is dead, period.
However, this is not true of the headset that you are trying to use. It is a USB input device and as such should work with more than one application.
Look in the Apple menu in 'About this Mac'.
It will show you which version of OS X you have, click on More Info and scroll to USB, it should list all USB devices that are connected.
Click on System Report and then.
Look for the headset and let me know what you find please Phil.