I suspect romances are the most sensitive to skipping dialogues. For Gale, if you go through the Weave scene (keeping friendly), you can kill the romance at the very beginning. If you ignore conversations, the game sort of assumes you need a second person interested in you and you have to get the jealousy scene. How the game chooses that "another person", I can not tell (suspect, it chooses from not actively turned down companions). But all and all, conversations and solid "no" is the key.
