Is it permissible to say: "O my Beloved, O Allah," by analogy with "O my Refuge, O my Shelter," and so on? And is it correct to describe Allah as "All Love," by analogy with His being "All Mercy" and "All Generosity"?

It appears there is no impediment to supplicating Allah Almighty with "Ya Habib" (O Beloved), because He is the Beloved who loves His awliya' (saints/devout servants), and He is Al-Wadud (the Loving), meaning the Beloved, as Shu'ayb (peace be upon him) said: "Indeed, my Lord is Merciful and Loving." As for applying attributes like "generosity" (al-Joud), "mercy" (ar-Rahmah), or "love" (al-Hubb) as names for Him, this is not permissible. Rather, one should say: He possesses generosity, and He possesses mercy, and one should say: He is Generous, Merciful, and Loving towards His awliya'. For the names and attributes attributed to Him are tawqifi (revealed and not subject to human reasoning or innovation).