I have a sneak toon around level 21, sneak almost 80 (perked). 1h around 40, archery 50 (perked). Bow is orcish, daggers are dwarven, both found. No gear upgraded via Smithing.
Playing on master, the vast majority of mobs I come across, even casters, take a
bunch of arrows from sneaking to take out. Basic bandits, novice mages, skeevers and non-frost wolves I can take in one or two shots. Nothing else. And forget about sneaky dagger attacks at this point -- barely scratches the surface. Again, low-armor casters I can take out with daggers before they know what's going on, but it's still only after a couple of dual-wield power attacks.
So I spend alot of time shooting, running, hiding, waiting for the eye to go away, sneaking back...etc
Just to give some perspective. People who say "yes it's viable" or "no it isn't", while not being dishonest, aren't really giving you the full picture bc you don't know if they're playing on novice or master or what else they've done with their toon.
edit: in the interest of providing the "full picture", my character refuses to use companions. As a thief/assassin, she needs to get in and out quick. That's what she said. Not my character. You know what I mean.
edit2: OP asked about
perking smithing -- I'd say you can get away without
perking smithing and not have too much trouble. However, if you don't even
skillup smithing, while it does seem viable, you're going to have a much harder, slower go at it.