Yea I’m not sure of OP’s ability and the requirements for games was vague. But IPX isn’t that big of a hurdle, DOSBox has an emulator for it: https://www.dosbox.com/wiki/connectivity
Bigger issues would be sourcing and playing some of these games on modern systems at all. And some dedicated servers can be a pain.
Correct.
The 1st century started at 1 A.D. and included 100. 2nd century started 101 to 200. Etc etc. If you change the 21st century to be 2000. You would to shift everything down. Eventually making the 1st century 99 years. Or creating a year 0 or using 1BC.