I think there's a few more things that need to be cleared up.
1. Do not set your receiver for 4 ohm operation. Ever. All that does is limit the power from the receiver to comply with certification standards and doing it could actually damage your speakers due to receiver clipping.
2. Since none of your speakers are 4 ohm, you should not set your receiver to 4 ohm. The impedance rating comes from speakers, not amplifiers.
3. Max wattage on speakers is not really relevant. It's a recommendation, but too many people put too much emphasis on it. Speakers do not require a specific wattage nor do they immediately explode or otherwise fail if presented with more than that number. (unless it's a LOT more than that number...)
