Shredded as, or before, bulking cycle?
I vote for before.
Ketosis is a little different for everyone.
Some will get knocked out of ketosis from eating any carbs. Some people can stay in ketosis up to around 50 grams or so.
You should shoot for zero (zero) carbs for ketosis. Anout 60% calories from fat, 40% from protein.
Peanut butter is not a good choice as it has a healthy dose of carbs.
Stick to meats and leafy greens. Butter is fine. Oils are fine.
No, on a keto diet you cannot carb-up pre-workout. That will knock you out of ketosis.
In ketosis you are basically sacrificing everything else to burn fat quickly.