Lord and Lady, eeeehhh I'm pretty firmly on the fence over it. I 100% agree that RNG heals are generally not great. It's also strange given that SE have typically backtracked on RNG healing abilities too. However, given it's a minute cool down and doesn't interfere with regular cards, it's not really a hinderance either. I can merrily sit on a Lady for the duration of the cooldown and it's easy enough to just throw it towards the end (If that's even needed) to try another pull. My biggest issue with the ability is why it needs 2 buttons? We've had abilities that go on cool down when initially pressed despite having a secondary press/effect since HW. I don't understand why SE are making similar mistakes Stormblood made all over again with this?
Astrodyne isn't that awful, at this point it's pretty much a given that getting the 5% personal damage is going to play second fiddle to optimising cards on the group so I just see that as gravy. It's PoM for AST in my eyes. You'll probably know this better than me, but the bit that has me puzzling with Astrodyne is how the optimal Divination phase is actually going to play out. I get the feeling that we're going to be going back to needing to hold Lightspeed again if we want to avoid clipping?
I'm with you on the 6.0 Divination feeling like a bit of a cop out for sure.
Regarding Glare vs Malefic, really this is just balancing something that should have been set straight years ago. AST damage took quite a significant step upwards when they got the faster cast and SE never really gave WHM much of anything to even that out. As you say, SE never really seemed to appreciate quite how big a change it made beyond simply helping casual players avoid stalling their GCD so much with card play.
As for AST vs WHM in progression, I think it's impossible to say until we see what direction the encounter design has gone this tier. If we see more along the likes of E8S with sporadic bursty healing and highly stern DPS checks, AST will be the pick for sure. Outside of that, I suspect it'll lean more towards personal preference.