"J. Clarke" wrote

So I'm doing it wrong when I use a piece of 12 gage aluminum as a pull
string for 12 gage copper?

Why not use a proper electricians fish line?

Not necessarily wrong, but do you really need to have a 15 amp and 20 amp in
the same area? It would follow that two 15 amp branches would be plenty of
capacity; more than even a single 20 amp.

If you want to mess with the 20 amp added circuit, go ahead. You will
anyway, right?
--
Jim in NC