A:AnswerHello,
We do not allow changes to our systems before purchase, but you can do that yourself if you'd like, as this PC is fully upgradable! Please note that depending on what CPU you change to, you may have to change the motherboard as well.
A:AnswerHello,
If you are planning on adding in 8GB of RAM, we recommend matching the stick the system comes with, since mixing different RAM models can cause compatibility issues.
A:AnswerHello,
Yes this system can run shaders in Minecraft. We are unable to provide specific FPS information as that is dependent on your in game settings.