Advantage/Disadvantage should only apply to combat actions (attack, dodge, block, and shoot). We had even decided that spellcasting only got 1 die for a singular action and was at disadvantage for a primary action (we may have not been playing with this, but we should be). All other actions need a talent or item to gain an advantage like danger sense.   I definitely would not want actions like tracking, hearing checks, or barter to automatically get advantage. You could even argue that shoot should not get the advantage bonus for a singular action.  

I think the default for everything needs to be one die. If you go into combat and are willing to be defenseless while you focus on your action, then you get a second die. I do think that if you're in your keep and you are focusing (in optimal conditions) on research or divination or something similar, then you could get a second die.   I don't like the idea about being at one die on singular and disadvantage on a primary. That's too severe.