Ok, one at a time...
1) gfg? Not familiar with the term.
2) I really don't know if there IS anywhere to DL premade chars...I'd MAKE you some badass ones, but I no longer have Nez...
Again, try Zoltar...he knows nearly as much about insta-charmaking as I do, he uses the same hack I did to build megachars from nothing in a very short time.
3) How to change a premade char's name, I do not know. Not sure if you can...you'd think renaming the save files would do it, but I'd be afraid of corrupting them and losing the char altogether. BUT, if Zoltar makes a char or two for you, he can name them whatever you want.
4) There is no official Bnet-sponsored server for Nezmod...we've gone through a couple privately hosted ones here, and I think the current one we're using for Nez is D2Maniacs...there's a thread elsewhere in this forum that should have the info you need to put in Battle.net Gateway Editor to access the server.