UPDATE: Finally got this issue resolved. Rather than trying the battery first option we changed out the entire phone, a new SGS3 and voila, everything is working as it should, although this new phone is configured with Android 4.1.2 and I don't plan on upgrading to 4.3 right away. The agent/dealer will hopefully resolve the 'battery drain' problem with the first phone which I firmly believe was a hardware issue with the phone proper, not the battery and not Android 4.3. Thanks to all for helpful comments and advice--this is a great forum.
Android 17 QPR1 Beta 1
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