For offline access, you just need to configure that once with the CIDR of your local network(s), and then the next time you're offline the server will allow auth-less use: you'll still be you, but the server itself won't attempt to authenticate you through the internet.

Settings -> <server name> -> Network -> Show Advanced -> List of IP addresses and networks that are allowed without auth

You can also toggle off some of the extra crap they are pushing:

Settings -> <your username> -> Online Media Sources