The trick for getting your crimped lines straight is to squeeze the handle before adding the paper. Now line the paper up straight and push into the crimper until you feel it hitting the wheel. Then start crimping.
For adhesive, I would suggest either liquid adhesive or glue dots. I wouldn't use tape either, since, like you stated, it flattens your crimping. Or if you want to use tape, add the tape to your un-crimped piece of card stock and then press your crimped piece on top of that.
To see samples made with a crimper, check out one of our first Way to Use it challenges