I’m all for indicators on choices, in an absence of save system indicators would greatly help making conscious decision instead of guessing and hoping that you understood what author meant.
As for the cons:
Just add more indicators, if the choice is important mark it so.
I already do that with the help of save manager, indicators would just make choice more transparent. It’s even more important in stat heavy games.
Depend of indicator, i guess. If it’s “This choice will lead to character X backstabbing you” yeah bit of a spoiler. But if it’s something “Try to climb the wall [Agility]” i doubt anyone great mystery would be spoiled.