You can't play an unpatched version of EQ because the EQEmu server is written to communicate with the patched version of EQ. There are countless changes in every aspect of the game since EQ began.
You can easily host a server and play on the same computer. You don't need a particularly fantastic computer to do it, either. I have a 3.0GHz, 512 RAM, 128 MB Video Card and it's way overkill.
To play "1-player mode" or with your wife, you can either set up a LAN server using Minilogin (search the forums for a LAN setup guide) or host a server online, which friends not on your local network could join. More complicated setups are possible but not recommended (nor officially supported) until you're very familiar with how EQEmu works.
Good luck, there's a steep learning curve to getting a server set up, but it's worth it in the end, trust me :P Feel free to drop by the #support channel on
irc://irc.eqemulator.net and ask for help if you're stuck.
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