For 98 Civic Ex coupe

Are ball-joints something I can do myself?

When replacing belts, how important is it to get the tension strength to factory specs and how do I do that?

Need to replace Pads and Rotors, Do I need to bleed the brakes?

Looking into getting an exhaust, thinking about either Apex-i WS c-b, custom Apex-i N1, Borla c-b or factory muffler off another Honda/acura with bigger piping. Ideas and thoughts please.