1 LOL mac address differences
i dont think it will work because of mac address differences.
2 You would be using that as defualt controls
can i use keyboard and mouse on the pc with an emulator
3 Xeon might be able to do it (considering its sole purpose is Halo emulation) but i dont know
Cxbx is the emu i have always used and i never tried the network options, so you can try those 2 emus (please google them, i dont feel like grabbing links, if anyone else wants to, thank you)