Wow. What a setup. :thmbsp: (You'd better believe that its saying "Technics" helps as well.

)
In all seriousness, I'll bet that sounds every bit as good as it looks. I don't know what to tell you about your cartridge and stylus, but I can tell you about what's going on with your speakers and receiver.
Technics is simply trying to say that you can use speakers with an impedance of 4 to 16 ohms if you only ever plan to play one set at a time. Yet if you plan to play two sets at a time, you need to use speakers that specify at least an 8 ohm impedance. Otherwise, the amplifier might burn out or fail. I think you'll be fine as long as your speakers all claim an 8 ohm impedance rating. This set places the speakers in parallel with each other when all are switched on. As such, the impedance drops with all four speakers running.