To address the OP looks like you didn't read Alisaie's HW tales from story where just like Renda-Rae has to watch helplessly an entire caravan of people die that she was a guard for from a cliffside collapsing during one of Thanaland's rare thunderstorms. Most of the caravan being swept down with the mudslide. It's why she took up the art of the Red Mage and put her on the path to try and be as good if not better than the WoL in at least where fighting is concerned.

Monbryda's death might have been a long time for the player, but it's still fresh for inside game time even if you feel that it's been a year or two.

Thancred's drinking and womanizing I think were twofold. One was they're both great ways to gain information. The other was how he was dealing with the guilt of indirectly causing Minfillia's fathers death. It's why he chose to stay away from her while she grew up and put some distance between her and him. When he started to try and close that distance the bloody banquet happened. Heck he even got possessed by Lahabreha cause he worked himself too much due to the guilt he felt. That he had to make his failure up to her. The man starts to slowly work through it starting when he punches Emmanellain after his blunder with the original peace talk interruption. Still not sure what you'd of want from him in the way of action when learning that if the source were to be destroyed that the remaining shards would also go with it.

Part of his growth during ShB isn't just learning to let Minfillia go, but to realize that Ryne is her own person. That she by the time the group chooses to go to Nabaath Areng is no longer the helpless scared young woman he rescued from the depths of Elumore and that she can take care of herself. That if things did start happening on the first and she needed help that she had a big enough support system he wouldn't really need to worry as much.

I guess Y'shtola becoming injured and being taken out for most of Stormblood doesn't count. Soon after getting her back in the post HW patches.