RE: Newbee needs help!!!
You should be able to use a receiver from a gas plane with no problems. The esc needs to either be programmable or must have the cut off voltage pre-set at a high enough level to protect the lipo. You don't want to discharge the lipo under 2.5 volts per cell. If your lipo is 2 cell it is likely that the esc is pre-programmed at close enough to 5 volts to be acceptable.
But it the lipo is 3 cell you need to set your cut off at a minimum of 7.5 volts. Most people actually use 3 volts per cell for cut offs just to be safe.
Lipo's need special handling to prevent fire and/or damage. Must be charged with a lipo charger at no more than a 1:1 ratio and must not be over discharged.