Add information, stop being vague.

1. Merchants - add a little clickable "i" icon to their window, which will then show information about them, such as that they change their inventory when you level up, and the item level of items they can provide you.
Same thing for Gamble Merchant, information about item level.
Same thing for Expedition Merchants, "items appropriate for your character level" on exotic coin info is way too vague.
Same thing for Waystones Merchant, they offer you waystones one level lower than the highest waystone you have finished, and refresh when you level up.

2. Orb of Chance - thats probably way more work so i don't know if it can be implemented. But in a perfect scenario this should be showing you what unique you can get when you hover over certain item, and the percentage chance of getting that, your decisions should be based on information, not just some random gambling. "Unpredictably" is a terrible word to see in item information, and misleading when it's actually quite predictable.

3. Vaal Orb - same thing with the "Unpredictably". Again, it's very predictable, and the information is available on external sites, put it into the game.

Im sure there is plenty more examples of things like that in the game, so everyone is welcome to add the ones that they have found/bother them the most.