If you are using window OS keep eye on "Task Manager" and try to find out highest resource consuming process. You can analysis the load and highest process. Keep enjoy coding.

No.

Just make sure you have a quad core processor.

For Android Studio, which is very heavy btw, No.... you don't need...even the Android emulator runs smoothly on the intel integrated card... what is crucial though is the ram not the gpu.

I don't think so. I'm using integrated into i3 and all works fine.