Hey Samuel,
Thanks for the appreciation.. mean a lot!

Yes, there are few other things i need to update in this post and already in my draft, i will post them soon.

Update :
For your question,
The location of supervisor binary depends entirely on the installation. If you install it manually or install it for a user it will be under /usr/bin or any other location you choose.

The location of Supevisor.conf file depends on where you place it. (Please check back my post updates.) For e.g I may keep it under user home directory or simply under /etc/supervisor directory and source it with -C option.

Location of custom config is also configurable. By default the supervisor check it relative to the supervisor.conf file location. So, to customize it you may specify the full path under [include] directive.

I hope this helps! Cheers!