The CMs will trade with you as long as you have a Disney copywright pin (i.e. it says "Disney" on the back). This applies to all traders, aged 3-103. Kids get to trade with all CM lanyards, adults can't trade with green lanyards.
As for CMs needing "to be shot" for appreciating the mini-pins, well whatever. They're not trading their own pins on the lanyards, and if I was wearing a pin lanyard all day, every day, I'd want to get something light on there rather than the heavier pins. But like I said, whatever.
To the new pin traders out there, you can see that this can get touchy and there is definately a "pin hierarchy." The good news is, this shouldn't really impact your trading with CMs. Just have fun. If you like the way a pin looks, go for it. You can always trade it away later!
One man's trash is another man's treasure!