Let me take a stab at answering your questions
1) I'm not sure if they are filtered or not
2) I plug my AVR into the high current outlet. If I recall correctly the owner's manual for the PF60 says something about usage of the high current outlets and says it's fine to plug a high current devices into other outlets besides the high current.
3) You're confusing the wattage rating of the speaker with the power consumption. Your denon is rated at 150Wx7, so that's only 1050 Watts that it is capable of consuming. It's unlikely that you'll ever draw that much power. Furthermore, what is the amperage rating of the circuit that is powering your A/V equipment? It's probably the usual household 15 amp circuit. What is household voltage in Canada? 120? 15 amps at 120V = 1800W. This is what Belkin is referring to. If you draw more than 1800W, you're going to blow the circuit breaker in your house.
Plug your stuff in and don't worry too much. The Belkin should be more than capable of handling the power draw.