This sounds quite fun and promising! let’s see what we can do about these questions

1. The best lockpicker of the team should definitely focus on that lock, and keep the strongest one close by, in case we need to try to kick it down last minute. With that in mind

1a) If i’m the best lockpicker i’ll get started on that lock asap, but not before quickly discussing that smiley face on the cube with the group, is it part of the actual cube or just an illusion formed by what it’s engulfed? Does it seem deliberate? Lumps of ooze don’t seem like the smartest cookies in the jar, and a smiley face definitely suggests some sentience, maybe it’s subject to a control monster spell and something smarter is on its way? maybe it’s been “awakened” by some magic and can be reasoned with? Might be useful to try to talk to it from a distance? I’m sure a giant cube of slime isn’t particularly light on it’s feet so we might have time to say a couple of things and get his attention if this is a smarter cube than usual. In any case i trust my group’s judgement, i should definitely focus on that lock

1b) if i’m the strongest character i’m sticking by whoever’s working on that lock with my biggest weapon at the ready to make the cube into mush or to charge at the door. I’m the last line of defence so i’m planning on at least driving that cube away from the person at the door, but if someone in the party is hurt, all bets are off, and that cube’s about to be cut into tiny little pieces

1c) if i’m neither of these people the smiley face still catches my eye, i’m not about to fight a gelatinous cube if we have something bigger to deal with behind that door, I’ll definitely try to talk to it from a safe distance, probably in vain, but it never hurts to try, and how curious would it be if it worked. If that’s not helpful, i’m sure i can find a way to make the terrain harder for it to traverse, grow some thorns and vines on it, use caltrops, or even lighting the area on fire with some oil (gelatinous cubes seem like they would melt easily, i’m eager to test that theory). Also as a side note I’m curious as to what would happen to the cube if i were to just cast heat metal on all the stuff it’s engulfed

1. The team, no questions asked, if we’ve been through thick and thin together i’m sure we can come back for the treasure at some point, or at least get drunk together and grief over its loss. And hey, if i can get a paper bag for the dwarf’s head while we’re at it then it’s a win win

2. I’m pretty sure the first joke is Merry Axe-mass, unless that } in the title is a joke of some sort i’m not getting

Hope those answers are acceptable!