I'm not 100% sure what it does, I think the option is there for advanced network configurations.
In general you'll want to leave it blank and let the server auto-determine what its IP is.
The language barrier is really being a pain.
I'm not sure I understand the problem, is something obviously wrong when you join the server or are you just worried that the console stops at "Unloading Dimension #"?
The filenames of some of your mods suggests you are not getting them from official sources, please read my signature for more info on why this is a bad thing.
Also, from BetterFoliage's CurseForge page:
I'm not 100% sure what to make of this, from what I can tell Java itself is crashing, I think when it tries to run Garbage Collection.
I'm afraid we'll probably need to wait for someone with more experience to chime in.