Crap, the more and more digging I am doing, the more it looks like FCPX won’t edit AVCHD natively, even though everything I read beforehand (even from Apple!) indicated that it would. Well, that sucks. I guess I’m just gonna keep all the footage on an external HDD and import the footage from there, creating only one copy on my internal iMac hard drive. I suppose that’s a solution, but I just don’t like the idea of double importing.
I’ll leave the thread as unanswered for a little bit longer, in hopes that someone may be able to prove me wrong (or right?) and that I’ve just been missing one simple step. Thanks a lot for all the help, everyone.