I wouldn’t give up on the hash modeler right away. It took me about two months to unlearn what I knew about polygon modeling and learn from scratch about splinemanship. I found that the tutorials on the net were useless for this, and that the best teacher was actually looking at the Lady Goodbody model and the model of that girl in the bikini with the sunglasses. Oh, and Keekat. He’s an amazing little thing.
As far as importing parts goes, if you’re breaking up your polygon model into chunks (as you would with, say, a mech) it ends up not so bad to animate. Just a thought. Also, things like space ships are fine. Character stuff, though, is better off done with splines. Once you get used to them you’ll find that they’re actually quite nice as they do all the hard work for you after you’ve gotten started animating with regards to flow and such.