I would suggest doing 'The Molecular Level' using The Brotherhood of Steel's scribes to decypher the blueprints and the quests you've mentioned will unlock after that. To start this question you will need to speak with Lancer-Captain Kells aboard the Prydwen. However, the quest 'A Loose End' references people and events that don't occur until after 'The Molecular Level', and 'Getting Technical' follows on from 'A Loose End'. I haven't completed the Brotherhood of Steel questline yet and like you haven't done more than multiple Quartermastery and Leading By Example quests (which are infinitely generating side quests and not story missions).
