Correct me if I'm wrong, but..
1. Yes, it goes in the usual mouse port.
2. That's right, no software necessary for normal operation.
3. It's particular about mice, since it is meant for serial mice only. So if your mouse is PS2 only, it will not work.
Combo mice (which support both PS2 and serial mode, and autodetect which to use) should work ok. I used to have a mouse like this, it had both a PS2 connector and a serial connector. Never tried it with the Mroocheck though.
I used to have a Mroocheck; it worked OK with serial mice, but I did not get it to work with a PS2-only mouse even though I had an adapter.