No one will regret nothing if things are done properly.
Yes they will. Because the way the Guardian is implemented in the game and that character's identity and nature are done, fixed, and will not change. There's not going to be DLC that will change who/what the guardian is. There is no viable or worthwhile romance there at all. If you haven't finished the game forget about the guardian entirely and find someone else to romance because you're wasting your time.
