I haven't seen that Fallen Knight skill yet, maybe that will have to be my next run. Expendable potions definitely sound useful and enjoyable, though I wonder if our current method of learning crafting items would be a bit too much for consumables? I'm not sure if some kind of found recipe books would be called for, or if holding off on salvaging potions for mostly intelligent characters would be a compelling choice. Either way seems like it'd make sense and would fit to me.
Excited about events and base building mechanics! One of my favorite things to do in Dwarf Fortress is going back and forth between an adventurer and building/evolving a main hub city for them in fortress mode. Maybe it's my personal bias :P but I feel like something resembling that would do well here. Not talking a whole fortress mode (Unless you want to lol), but having a changing base with minions I think would go a long way towards feeling like you have an impact on the world beyond it's physical destruction.
One thing I've been wondering about, are you thinking about expanding combat at all to multiple z-levels? No expectations here as I know this is something that can be very limited to engine and overall game scope, but I suspect it's a question you might get increasingly going forward. Thinking about it, I had a thought of maybe a fudged 2.5 dimensional combat, where a player could climb a tower or other sort of raised emplacement where the field of view is expanded out further for you to rain destruction down on a high number of enemies before descending to the ground melee. I dunno, just ideas!