I have read through the owners manual and the reference manual.

I would be interested in some clarification, or verification.

Can you layer 4 sounds.. I know there are 3 right and 1 left,
No it cant

but in non split , can the left sound be layered with the 3 right? It also appears that sustain is not possible for the left sound.. Is that correct?
It is possible to select sustain for left ( press Direct acces and push the foot pedal)

It also appears that chords do not appear in SMF's unless they are embedded . Is this true?

Can it read karaoke files (CDG and MP3 contained in Zip folders) Or do you have to convert to a Yamaha format?

[i]Genos dont read zip files , unpack them in a folder you can[/i]

How large of a flash drive can the Genos read ? No idea

Is it possible to read a USB drive containing for example 30,000 karaoke files in a single folder, and use a
search feature to locate a specific song?

There is no sampler? Is this correct..? Yes
Can you import a wave file sample... for a tone, not a pad? With YEM you can do this


Would be interested in the same points with the SX900.. = the same