Also, the �moral� argument that it is OK to sample freely an acoustic instrument (piano sax �) but not an electronic one (T2 G70 keyboard �) is absurd and contradictory when the desired effect is the same.
I don't think you understand the difference at all between sampling VS re-sampling.
SAMPLINGTo sample a real piano requires a rather large investment of time and money. Sound engineers, studio time, large setups, and expensive hardware to do the recording and mastering.
All this time and effort costs money, and so recordings made on the day are copyrighted. They are NOT made free though public domain.
RESAMPLINGResamping happens here when someone takes a Tyros 2 and tries to extract Yamaha recordings out of the instrument. The very same samples that Yamaha spent all the time and money recording, and which they also copyrighted.
All the other issues you mentioned don't have any grounds if you understand what is being said here.
Kind Regards.
James.