Note that everything I say is purely my opinion, and also isn't your biggest concerns, since this assumes you even get a large enough player base on your server.
To give a very small insight, global bans across eqemu are rare (I'm not even sure they happen?) and extremely difficult to ensure validity due to the nature of the internet. Since creating an account on EQEMU is free, if someone is tenacious enough to try to circumvent security, they inevitably can create an account even when banned. There's no easy way around this. That aside..
You can ban accounts on your server, IP based, and that'll negatively impact cheaters. If they're determined they will try to log in still, and you can just remove the account and they lose their gear, permanently suspending them, and that's really the biggest punishment you can give, start over.
Some servers support and encourage Macroquest 2 Usage. MQ2 has some typically off limit services, like mq2warp, mq2nodoors, as well as ghosting, and other sort of manipulations that while eqemu has some generic protections against, due to how players may abuse it, could bypass detection. (If you go to the hackers table you'll see this). Other tools, like the map display feature of mq2, or showeq, can be difficult to detect and there are no widely released security fixes for these services. This is because if you open source the protection, you create encouragement for players to circumvent the protections. An example of someone with a MQ2 protection is P99.
People may spam, harass, or do other negative things as well, and some times based on your build of the EQEMU source, they may take advantage of bugs and exploits (especially since your server has customizations to native eqemu, that adds even more steps of vulnerability).
It's just an endless hole of filth and good faith that is always a fight, but are small notes that surface while juggling attracting players.