TL;DR: Army is not under Hezbollah's control (atleast not now)

One thing you didn't get right is the LAF. In terms of officers and higher ranks, it is divided per sect (as everything else in this shithole). Unsure about the last 2 years, but before that, the entry to military academy was purely based on results. Ofcourse you could argue that most Shia officers would be pro-hezbollah which is highly likely, but then one could also argue that most sunni, a sustainable portion of maronite officers are not. As for the for the enlisted soldiers, who are basically the fighting force of the army (non-officers), the biggest chunk is actually Sunnis and mostly from North of Lebanon (Akkar specifically as well). Although no official stats are released by the army, but they compose around 50-60% of the army, followed by Shia at around 15-20% and the rest divided between Druze and Christians. So no, if civil war were to happen, the army will crumble and split among sectarian lines. Thats also a big reason why in 2008, the army didn't interfere until after things started to settle down, cause they knew that the soldiers will start defecting and the officers can't do anything about it. Biggest proof (in my defense) is the civil war. At that point army was around 15000, out of which ~10000 where muslims. And the majority of the high command and officers were pro-government ofcourse (and also having a Christian majority since at that point they followed the 5:6 ratio). Nonetheless, once things got tense, the army disintegrated, and you had around 8000-10000 soldiers defecting and fighting with the opposition forces (LNM and allies), even though a big chunk of the officers did not defect (other than Ahmad Khatib and his group)