I always advise against using these so called prohormones. They are not "new" compounds, but compounds abandoned years ago because their rewards were simply not worth the risks. They are typically very weak, and will really fuck up your bloodwork. HDL goes through the floor, LDL skyrockets, your liver values all get raised and blood pressure issues are the norm. The tried and true steroids are really the safest, not to mention backed by years of research.
With respect to your questions, I would stick to 50mg and see how you feel. I've had to cut cycles short because I was quick to jump the gun and up the dose and ended up feeling like shit. PCT will probably not be terribly helpful, but if you want, try 50mg clomid or 20mg nolvadex per day for 2 weeks.
There's no answer for your calories question. It depends on your metabolism and your goals. Some people can eat 1000 cals ove maintenance and just gain muscle. Other people gain just fat. It's something that you have to learn for yourself through trial and error. Xanax will have no interaction issues, but will result in shitty workouts.
