1) If you press ESC button on your keyboard theres that Options button, click it. On the Interface tab, scroll down until you see that "Arrival Chat Name Type"? If you click it you can choose the option "Dont Show" which will stop those messages.
2) Im not sure what you mean
3) On the Controls tab (still in the Options menu) there is Front, Back, Left, Right you can change them by clicking one of them then hit the Change button below. When you press that button hit the button on the keyboard you wish to replace it with.
4) Yes, you can click the right CTRL button and press and hold D or A UNLESS you have changed that.