Well, you are directly copying/using any of GTMs features, maps, resource pack then that's stealing and that is enough to get you perm banned from GTM. We are not cool with thieves. However, if you are talking more like, taking inspiration to make your own thing, then that's different. But I will say you are entering a bit of a slippery slope here by discussing other servers so just be careful around there not to unintentially advertise or etc .
c'mon sky I'm not dumb. I was never even thinking about staying any part of the GTM map when I made this thread. I'm talking about features like backpacks and Hitman mode that are really helpful to have on a GTM server. And screw intentionally advertising rules, I'll ad all I want: Play Minecraft Survival! Great gameplay, amazing communtiy, beautiful map. Join today through the single player option on the Minecraft menu screen! Haha, thought I was gonna advertise. I played GTM to long to be that stupid