It's incredible so far. I just made it out of Act 1. For the most part, you can come up with plans and ideas on your own, and they'll usually work, which makes you feel like a genius, but I have to call out two times that this specifically did not work the way I thought they would.
some light spoilers ahead
Early on, there's a target that you have to either eliminate or side with, and I choose to side with them, with the express purpose of getting them to let their guard down so that I can separate them from the group and eliminate them. The dialogue options even allude to the fact that this is a strategy they want you to use. This target wants you to sneak into another (good) faction and open a gate for a bloodbath of an assault on that faction, but the target also leaves their battle plans out in the open. So I figure I'd steal the battle plans, give them to the other faction, and just not open the gate, and then that target dies. Well, it doesn't work that way, and progressing that far along with the target invalidates the other quest entirely. Bummer.
The second is a fight right near the end of Act 1 where you've got to eliminate or side with a target again, in a room with a lot of lava, some slaves you can try to rescue, and a lot of enemies. Depending on how the dialogue goes right before the encounter, you either side with the target against the room full of enemies (but the slaves die), or you fight everyone. There are about 15 enemies in the room, which means they get a lot more turns than you, and since they're all grouped in that room, there's no real way to isolate them and take them out stealthily ahead of the encounter. I tried using a bard Performance to get them to all clump up so that I could push large groups of them into the lava, which was fairly effective, but then the slaves would join that group too, and it was very easy to aggro them. Worse still is that the slaves will happily fight you if you aggro them, but they won't join you to fight the other enemies in the room that enslaved them, let alone the target you're trying to eliminate. The only way I found through it was to reload an earlier save and to make different dialogue choices with a particular NPC so that some of those 15 enemies end up on my side in that fight when the time comes.
end of spoilers
The game usually lets me get away with whatever crazy plan I come up with, but I just wish these two points so far were a bit more flexible.
For the fight in Grymforge you're talking about, there's also an opportunity to get some of the duergar on your side, which makes the fight a lot more manageable.
Also, the game never explains this, but you know the buttons in the bottom left of the screen during cutscenes? You can use these to trade with characters that don't normally have an option for it, to switch party members to sneak around while the one in conversation distracts an NPC, or to attack before a cutscene finishes playing out. Doing these things can affect the outcome of game events!
Trading specifically I'm not sure if it changes anything, but you can buy things from NPCs that normally you can't trade with. I do know that stealing from NPCs and attacking before a cutscene plays out can change the survival of some NPCs.
One thing I learned about the game fairly early on (actually in that same area, with a certain imprisoned bear) is that once you do something that makes NPCs hostile, they are going to stay hostile for good. That's not to say there aren't opportunities to flip allegiances a bit, but going fully subversive isn't well-supported. And to a degree, that makes sense; a good DM's going to make it difficult on you, because once you're seen with the enemy, it's going to take a lot of convincing.
But again, my expectation is that I had other ways to go hostile against these folks, especially after the goblin camp. But that scenario is basically set up to make that combat encounter next to impossible, but I didn't know that ahead of time, because after you clear the obstruction, the state of the map changes.
Yes, there are a couple of situations in the game where one can end up in a dead end situation, and that's probably the easiest of the bunch to stumble into. The player pretty much has to either make a deal with the chief ahead of time or just not do the battle. It's not ideal, especially since it's likely easy for a player to go into it when needing a rest, too.
For your second fight, you can actually get above all the enemies (there's a platform, to access some other parts of the map) and just completely break the AI, because they can't get to you. I don't remember if the slaves even joined the fight, but they all survived.
You can use this "tactic" in multiple locations, if you're not above cheesing fights. If the enemy doesn't have a ranged attack, or have no easy way to get to you, they just run in circles.
you can either jump to a small outcropping down below, near the "entrance" of the big room, where the slaves are, or on the other side of the map, are a bunch of dwarves trying to go through yet another wall (these have like two goats with them), and go from there.