The latter two have a lot of nice QoL changes and imo more fleshed out stories, but all three are fun. There are mod that have recreated the entire first game in Dragonfall, so it might be worth checking out (have not played the mod myself)
Big Bad Evil Guy
Personally I would allow pouring out oil to not break invis, but depending on the type of enemy, they might get perception checks to see if they can correlate oil pouring to mean someone must be pouring it for the players location. Although if they would throw the oil at something it would be like making a throwing attack with an improvised weapon.
Using the tinderbox I’d rule as attacking the oil in order to cause fire.
I feel like those moves equate to item interaction for pouring the oil right where they are, but deliberately lighting something on fire with a tool requires both more focus, intent and deliberate action.
Also lots of spider in both. Now I’m wondering what the Underdark equivalent of a koala is.
Mom, can I have Fix This? No, we have Fix this at home.
Fix this at home: Fix boat
They are, but the quote refers to the dark elves in warhammer :)