no its not pot. lower grade soils can come with viable seeds in them. i found some plants that look like those in my cheap walmart potting soil, i don't know what kind of plant it is though. and don't be so gullible :P.
you sure can use soil from your backyard. that is, if you want shitty soil that has lots of bugs that are going to eat and kill your plant. otherwise drop 2 bucks and get a bag at the store...
you don't need to worry about the freezer, its not necessary. what i did was just stick em in a wet paper towel and put them on the warm spot on my computer (in a bowl of course). just make sure the paper towel doesn't dry up or they'll die. i've gotten 18 out of 20 to germinate this way over...
i have a japanese maple as well and its leaves look nothing like pot. they look more like maple leaves, believe it or not... and not to mention trees themselves look nothing like marijuana... you do know they're trees right??? probably not the best thing to mask pot with.
actually, from what i hear hps watt for watt are cooler than the equivalent of cfls. so in theory that 150 hps puts off less heat than 150 watts of cfls. i can't say i know for sure though since i've never used anything but cfls.
its all hype. they're just trying to get you buy their product. every plant "grows wild" and drops seeds to propagate. you're just falling for their sales pitch...