Hey, how's things going?
1. Yes, 10 minutes I have heard is fine, I generally do 2 30 minutes with 30 minutes of steeping after each, but as I said I've heard 10 is fine.
2. As far as vinegar goes, about say 15ml or so should do fine and only one the first brew never messed with doing it by the liter either, many of us on the Aya forums don't do it that way. I never do more than that. With Mother Vine, I want to say I ended up doing about 30 or 40 ml for the entire batch. You really only need the vinegar (in my experience) for the first pull, after that it starts to pull it ou on its own.
Quick question though: are you only brewing and drinking the chacruna?
Good luck, and safe travels.
Remember, respect Mother Vine and the Queen of the Amazon and they will treat you kindly in return.
Much love and peace