* If you're just starting out and don't get any players within the first few weeks, that doesn't inherently mean that your server is going fail. Just keep making changes till you find something that works and is something that you would want to play yourself.
* I notice you talked a bit about how your other servers were more unique than those with 80+ players and you still considered them failed, unfortunately most of the time the type of content you have and how unique it is won't attract players unless if it's something that is absolutely groundbreaking in Gmod. Most of those servers host generic Gmod store addons, yet they have 80+ players because the community for them is dedicated
* If you're serious about running a community, you're going to have to be the person who can handle all the situations. Players usually look to the owner or some figure head in the community to see if they know what they're doing and that usually determines if someone stays and plays on your server.
Also I know quite a bit of GLua, if you need any help in that regard shoot me a PM and I'll give ya my Discord info
& nice Avatar :D
TL;DR
Focus on making your server enjoyable, make something that people WANT to play, and learn how to manage a community properly. Players usually come in time if you really excel at these things, and if you can't do that maybe reconsider.