A milliamp is just one thousanth of a amp. A typical battery current drain is around 15 to 25 milliamps that is used to keep memories alive in devices. That is a low enough drain to keep enough charge on the battery to be able to start the engine after weeks of sitting. Two amps of current drain is hugh and will be enough to drain the battery overnight. Hopefully the trouble will stay away but if it doesn’t the trouble should be pretty easy to pin down if it doesn’t go away by itself intermittently.
The radio trouble may be due to a disconnected antenna connection to the radio.