Sort of depends on what the control-data circuit wiring was shorted TO external to the ELT --for example like a 32 vdc bus bar or any power circuit or sneak circuit.
Very true, but this would almost certainly fry the IC which would usually lead to an open circuit somewhere along the path to ground. A dead short of the battery via a damaged IC is also likely to result in an open circuit condition. I'd also be surprised if there wasn't a fuse or diode to protect the battery itself from a short circuit condition.
An internal short circuit within the battery is a much more likely cause of a high current/high temperature condition.