Just a couple of points to add to the above;
1) I don't disagree with you on the Chakotay/Seven thing, but how much time did pass between "Scorpion" and "Endgame"? If enough time had past...maybe. It would have been alot better if they had shown the progress of the relationship.
2) I think the Klingon "aquired" the device on his own.
3) Agreed.