I don't wanna constantly worry about soul trapping the enemy I'm about to kill. It makes more sense for me if enchanted weapons didn't have a number of uses.
There's numerous other ways apart from soul trapping to recharge you weapons, but if it's something you feel you need;
http://www.tesnexus.com/downloads/file.php?id=3227
It certainly can be thought of as an exploit, much in the same way as the bashed patch option of unlimited rings & amulets.
Just my opinion, but the game becomes easy enough after a very few levels.