As a long time lurker ServerFault is infamously known for its hostility. Several times I have considered reporting certain users due to their consistent history of attacking the OP and arrogance with their knowledge. That doesn't make a healthy Q&A site.
I also disagree with the idea that eliminating the "professional capacity" requirement will drive experts away. Take a look at StackOverflow's top monthly users, most have large amounts of reputation and experience. Even with the massive amount of low quality questions they are still doing fine.
In this case the main problem is not the question itself, its the broadness of the question. To me its perfectly reasonable to close the question as NARQ since building a public server means talking about OS level security, firewall security, application security, secure coding practices, etc. That's a lot for a single question
What I do NOT agree with are the multiple users who flat out attack the OP. Yes, in an ideal situation you would hire a sysadmin (or at least outsource it). However, in an ideal situation you would also hire a lawyer for every single non-critical law question you have instead of googling, hire a general contractor to install a dishwasher or stove, you would never fix your car yourself and instead go to a certified mechanic, and you would never attempt repairs computer or phone problems by yourself. However, I bet most people do things like this on their own even though there's risk of damaging something but ended up doing just fine in 90% of cases
The proper response would be similar to law questions: "IANAL, but..."
The proper and best thing to do is hire a sysadmin or at least outsource it. They will know how to secure the system better and manage it in a production environment.
If this is absolutely not an option, the following resources will be helpful in getting you started. Note that you have real risk of suffering downtime, security vulnerabilities, and system instability, but these resources will attempt to limit those. Try to make it a goal though to have a sysadmin as soon as you can
- link to the several hardening Linux/LAMP questions
- link to a description of different services
- link to why desktop GUI is bad on a server (multiple questions on this, could also use Windows Server Core as an example)
Now was that so hard? You've made very clear this is the wrong way to do things and may cause bad things, but have provided a long list of resources to help get the OP started. This both discourages the behavior but answers the question in a nice easy way. You get the best of both worlds