We've been running minepacks for a few months now and players have things stored in their back packs.

We are now setting up a bungee network and would like the backpacks to link between worlds. I did not find anything in the wiki about bungee setup. So i have a few questions.

1.) Does minepacks need to be installed on all servers + proxy, does it ONLY need to be installed on proxy, or does it ONLY need to be installed on backend servers and NOT proxy?

2.)Im assuming mysql is needed so servers/data can be linked? How does one go about transferring existing data without losing any of it? Figured out this part

Minepacks must be installed on all servers (but not on the proxy) that should be able to use the plugin. All your servers must use the same database settings (and I would recommend to set all the other config values the same to, or copy one of your config files to all your servers).
When using a proxy server you should set the UUID_Type config option manually since the plugin won't be able to figure out whether your proxy is running in online or offline mode.
Also make sure to enable the UseBungeeCord config option.