in terms of safety, munich is pretty safe even for helpless maidens in the night. backstage have plenty of security people who in my experience are quite friendly if youre friendly to them
generally its a very peaceful place, even when the music is black death metal etc and the kids are jumping all over each other.
try and go on your own. worst case scenario, you go, have a beer, see a band you like and head home.
of course you might make a friend. you at least have the band in common and they might know of other shows that you might like. dont be afraid to speak english to people/let them know your german isnt very good.
as for "some people here dont like chinese". i doubt that any stupid racist gobshites are going to be going to No Use for A Name in the Backstage.
hope you have a good time