Have all involved in this discussion read these articles ?
http://www.kerisattosanaji.com/KERISANDNAGA.html
http://www.nikhef.nl/~tonvr/keris/keris2/origin.html
IMO they're very important to read and digest whether you agree with the conclusions or not .
I personally come to the conclusion however disappointing it may be that the keris and its true history are lost to time and that discussing and interpreting the meanings are like trying to hold an egg with no shell .
There is no B&W answer , only opinions and interpretations and these vary from each societal period that the keris has existed through right up to the present .