I've personally never heard anything about blood type and that effecting how a drug works in your body. But I will tell you that everyone has a unique expereince with steroids. Some guys are going to be more sensitive to strong androgenic side effects. Some guys don't do well with compounds that convert highly to estrogen. The key is starting with test as your base and then in followiung cycles, you can add a new compound. See how you respond to that. Through experimenting, you will see what compounds work best for you, over time and what ones you want to stay away from.
As for blood letting, phlebotomy is a great idea, for AAS users as well as Non-AAS users. Over time your blood gets thicker on cycle. If your RBC gets too high, it can be a strain on your heart. A simple treatment is theraputic phlebotomy. About 8 wks into a EQ cycle, I know it's time. I start to feel out of breath and tired. My face turns red quickly, even when BP is fine. If I donate a pint of blood, I feel back to normal the next day. I would suggest donating once every 3-4 months. Not only will it help in this way, it will also help you to detox heavy metals out of your system