I have continued playing around with Nicecast and realized that an
adjustment was in order.
There is a problem in using Nicecast's Auxiliary Device Output to
monitor what's being recorded, I can't hear any effects applied (i.e.
reverb, eq, filters, etc.). So I dumped that filter and used Detour
(from Rogue Amoeba again) to send the output of Nicecast to Built-In
audio. Everything else stays the same.
With this setup, there still seems to be little or no latency and you
can hear the effects applied. The effects will be applied to any audio
input (i.e. reverb on any song being played) but you control this via
the dry/wet mix control in the effects panel.
Here is a screenshot of the various windows on my pb for reference:
While Nicecast and Detour do cost money, at least the demos run without
any inserted static for 20 minutes each session so they can be used to
create a test podcast of at least 10 minutes or so.
While this works for me, it might not work for everyone. There is still
too many pieces in this puzzle but hopefully an integrated app will
make it's appearance.