My views on Imprinting is pretty well known among my friends. And if I still have that line in my signature, here too.
The wolf who imprints seems to disappear inside the bond they have with their imprintee, what they want no longer matters, any hopes or dreams they had no are not important to them, nothing is beyond the one they want to make happy. This is utterly wrong to me.
Imagine if you will that Seth grows up some and he wants to be a doctor or something and is going to school for it, then suddenly he sees 'Her'. Suddenly his dreams of being a doctor no longer matter, his life long dream would be thrown away like it was worthless in attempt to make her happy. Yes if they were like Sam and Emily, the girl would make sure he followed through with his dream. But girls who like twilight want a guy who would think of nothing but them forever.
How is it romantic to know that this person has no desires or really any personalty outside of their desire to please you and make you happy?
Imagine if a wolf had imprinted on someone like Lauren or Rosalie (When human), a very selfish person who would just love to have a puppy servant around to do anything they wanted. If a cruel person was the subject of an imprint.. they could have that person do anything they wanted and they would willingly. Imagine if Nessie grew up and took after Rosalie.. if she asked him, Jacob would bring her human victims each day with a bow around their neck, because nothing matters but her needs and happiness. Its seriously unhealthy, something to be avoided and I hope Seth doesn't Imprint on anyone, imagine all that energy and love of life gone forever, just to serve someone else's desire.
As for what would happen is the imprintee died, the wolf would be completely shattered. Imagine if everything that mattered to you was suddenly gone. Imprinting means the wolf has nothing outside of you, if you died they would suffer greatly. If they had given up their wolf form they would surely die of a Broken heart (A real medical thing), if they still had their wolf form they would do what Taha Aki when the third wife died and lose themself inside the wolf till they disappeared (Not sure what would happen to them, because if that story is true.. Taha Aki would still be around) Or Jacob when he left in Eclipse.
Sorry for the rant.. and away I go...
R.I.P - Jacob Black [Died August 2nd, 2008](Page 360, Book 2, Breaking Dawn)