Agreed.You should definitely get a torch, it's great for creme brulees and adding a bit of color to meats after they've cooked.
But for the purpose you're describing? No way. A good stew depends on good fond. That's the little dark bits stuck to the bottom of the pot after you've browned the meat. That's the stuff that gives a stew its rich deep flavor. Without it you'll have a watery stew - something will be missing and you won't know what. So save the torch for finishing a dish, not for replacing the most important first step in a stew.