RE: 2 planes differnt battery voltages
No the Power 25 motor is not enough for the electristar. You would need something like the Power 46.
and a 60 amp ESC, which would require the same battery as the electristar. 14.8 3200 4S.
The power setup you have now would probably work great in an E-flite ultra stick 25. with the
throws toned down you could use that plane as a trainer.