Thanks for looking through the favorites list.
As many of you are probably aware, this list is so old that it pre-dates life in our solar system :-]
I receive emails all the time from people who want their channels added to the favorites list. But it takes time to vet channels, check them before each release, get permission from channel owners to add them to the list, make sure that their content is legal/safe/etc. Over time, the will to do this gradually faded.
If you'd like to give this a go, I would be happy for you to curate it :-)
As for adding a network column to the favorites treeview dialog: I would have to find a custom dialog control that supports this and transition the existing code to use it. Not sure how difficult that would be.
That said, on my to-do list is an item that states: integrate the channels list dialog and the favorites dialog into the channels list window.
Both of these options would take time/work and may not be accomplished soon.
In the meantime, you could still come up with a list of curated channels, network-specific (since each channel allows you to specify a network), and we can move on from there.
The only issue is that, in the past, removing channels was always a sensitive issue, especially if a channel has been around for a long time. But it would make sense to create a list of genuinely useful/interesting channels for the default networks.