questions about the witnessing...
after building and running it in a container, what is required by the witness in order to start witnessing txs and gaining clients trust? Is it automated once you have the container running, for the most part?
It's up to the community to decide on criteria for a witness, but
I would personally expect more real word reputation, not just in trading (e.g. if you are a google, you are OK with me

).
One way to become a witness is as follows:
1. Run the witness code on your server
https://github.com/byteball/byteball-witness. To be considered seriously, you need to run it on a server that is well connected and always online. Running this code alone won't make you a witness automatically, you'll just periodically post your units to the database (and spend your bytes by doing this).
2. Campaign here and elsewhere trying to persuade everybody that you would be a better witness than somebody else and they should change their witness list by replacing some other witness address with yours.