[Server Crashes On Startup]

Rotten Flesh to Leather mod is giving you issues maybe does it run if you remove that mod?

[Finding a server]

I don't know of any servers that use Star-gates.  But I do host a home server with around 5 active players and we have Galacticraft and we use RF tools, Waystones and other mods that do the job.  Check us out at peptopia.asuscomm.com