So the lockpick roll… I’d use one roll to determine the outcome overall. I wouldn’t require a lockpick and then a stealth roll to pick the lock quietly, and then a stealth roll to open the door, and another to move quietly over to the cook.
I actually ran a 5e oneshot this weekend because I travelled to meet up with some friends for a birthday. I used several alternate techniques than standard 5e ones.
I let the rogue lead a group stealth check. I had the other two players roll for their characters. Success on their roll would give advantage to the rogue. Failure would give disadvantage. If they split, the rogue would roll normally. The rogue’s roll then applied to all members of the group.
I had a situation where they needed to climb a cave wall, and there was some time pressure. The cave wall was 80 feet. I didn’t have them make multiple checks based on climbing movement rate. They just had to make one roll. One of the players failed, so the penalty was not that he failed to climb the wall, but that it took him a long time. This mattered for the next encounter, due to the time pressure.
I used clocks to handle a couple of complex skill challenges, and made them player facing. There was a ritual being performed and when the clock filled, it would be completed. Another was for reinforcements to show up. An argument could be made that both of these things were beyond what the characters would know… but it was trivially easy to tick the clock and then narrate something that the characters observed (first tick was a goblin yelling down a side corridor, obviously calling for help; next was howls and growls echoing down the corridor in response; finally torchlight and shadows of additional enemies seen on the tunnel wall).
It all went well. The game ran fine… arguably smoother in some ways, though I can’t say that for sure. But one of the players… the birthday boy, who is easily the most trad-minded player in my longtime game group, commented about the “rulings” I made and how he thought it really enhanced play. In particular, he really liked the way the clocks helped portray the tension of the mounting threat of reinforcements and the ritual progressing.
Now… having said all that, I realize that not everyone would love these changes I made. To be honest, I was a little nervous to use them in a game with the birthday boy. But that doesn’t mean they can’t work. It doesn’t mean that there was anything more quantum about this game compared to others. It didn’t result in a bunch of “metagaming”.
What it allowed me to do was run a game with no prep, and to challenge the players and their characters in a way that worked and which didn’t need to be done ahead of time.