How much do you weigh and what is your total calories?
Peri workout is not conducive to Keto. Do one, not both.
1) Yes, that is your carbs for the day. But, as no two people are the same, play with it. I found my max to be 50g. After that, I went out of keto to easily and had to compensate.
2) as per the guidelines, avoid fructose. Gatorade is bad for that. Never tried Karbolyn but heard good things. Stick with that. Plazma is pretty good also.
3) No one can answer. Up to you. Give is a try and see how you feel. I personally hated it. I always felt great on pure keto. I actually dreaded the week ends until I learned to control myself and keep the carbs clean.