Thank you, everyone, for your responses; I apologize that it took me so long to get back!
Buntaro, I appreciated your thought to go to Japan and just learn on-the-spot there. Although I want to keep living in the US, I certainly haven't dropped the idea of living in Japan for a time. Thank you for reinvigorating my thoughts about that.
Musicisgood, thank you for the note on John Deere - it'll be interesting to look into them and see if there's anything I can do. Of course, if by some chance I wound up with them, I would have you to thank for the idea!
Salyavin, fortunately, the state I live in (Minnesota) has the Japan America Society of Minnesota and a weekly conversation group, so I was thinking of jumping right into that. Hellotalk is also a great idea on top of that, and the Google Groups link you sent is something I'll be looking into. Thank you so much!
Both Buntaro and Salyavin mentioned specialities. My Japanese professor recommended this same thing, and the more I've looked up about translation, the more I see that specialties are a common theme, so I'll have to think about what I could potentially focus on in that area. I recently met a translator who works at an automotive company, and he described similar things to me (lots of speciality language, so the first few months were rough for him). I am sorry to hear about the student who found the import/export company work too much! That's the sort of situation I'd fear for myself at my current level; but I'll have to keep working hard and not let that abstract fear inhibit job searches.
Also, the person I met mentioned that he went to grad school specifically for translation. A couple other places I've looked into required Masters Degrees. Is a move like that recommended across the board, or if I study hard enough on my own (both in Japanese and about the practice of translation) is translation an attainable goal?