RE: How do you power your war birds?
The only reason to not have a y-harness on two batteries into the same port of the RX is if the y-harness shorts out some odd way. Other then that, the only thing you do by putting two battery packs on a y-harness is increase the mah capacity while creating a much more sustainable voltage level since both packs wouldnt be loaded down as if only one pack were in use.
Yes...you can put an rx battery pack on a y-harness on a separate channel like rudder or whatever. Just rememeber, you need to have an on/off switch for THAT battery as well as the main battery.