I would definitely like to see the two dice rolls for advantage.
There's a mockup on Reddit, which looks nice for 5 minutes work:
https://www.reddit.com/r/BaldursGat...on_can_we_see_actual_rolls_vs_actual_dc/Larian might be worried about it being too confusing for new players, but, there is always the dreaded "O" word: "option". If on the Gameplay tab, there were two options:
Simplified Dice Rolling (the default), which is the current system, and
Detailed Dice Rolling, which shows Advantage/Disadvantage and Guidance rolls (if applicable), and the DC is fixed, but your modifiers are added after the roll, which many people like and would find less confusing.
This isn't a super-high priority. Another one on the "nice-to-have" heap.
No
You shouldn't magically know if a person is adamant or easily persuaded from his/her position. I could see the DC being shown maybe if you make an insight roll, but in general this should be hidden.
I agree, you shouldn't be able to pick a choice, check the DC, then back out, that makes it too easy to succeed.
I like your idea about Insight being useful for showing DC of checks before rolling. If you fail the check, you simply don't get the information. This probably wouldn't even require any additional Narrator lines, or at best only very generic ones.
In fact, Slapstick, I think you should post a thread suggesting that idea. Or I could, but give you credit.