Absolutely not. You bought the license (or 'lease') and technically not just that copy of the software itself. Go for it. I do it all of the time, because to be frank, ripping a copy off of disks that I've bought is too time consuming and stresses out my system too much to do it, especially in the case of movies, (and yeah, even with 4GB RAM and Core 2 Duo), so I torrent instead to speed up the process. I've never had a problem. Up to you of course, but I really do not think that they can go after you on any grounds if you have the product key/license.
As for ripping copies as soon as you get the new software/disks etc.: this isn't always possible because of the spyware security crap they lace into the disks. It takes more experienced people to crack that and get rid of it and to then unlock the contents so they can be copied and whatever else you want to do with them (ESPECIALLY software and movies). This is reason No. 2 that I personally torrent instead of rip as well, because I'm not a programmer and can't do it.
Oh, and FYI... the FED's predominately only go after people who are moving a heck of a lot of data over Torrents (we are talking over 100GB's in a week or more here). Pretty sure you will be safe with this bit of software.
This all said, be smart and DO NOT download torrents that have little or no information, and always check the feedback or comments on them to make sure its legit and that there aren't any 'extras' in it!