hey all after some comforting advice ! ive just bought a focus st170 02 plate. few questions to ask.

Are they usually a rattly noisy engine on general tick over ? its not really noisy just rattly? sounds metalic i have heard they can be noisy just wondered if its true ?

also i have slight leak nothing massive coming from rocker cover i have ordered a gasket from partbox (only place i could find one online) was going to change myself is this easy or recommended?

finally the old classic question i wanna make it fast as possible i know its never gonna be rapid but i would like to achieve 200 bhp. just wondered what the best exhaust, induction kit and map is? ive heard dream science is best but cant find one for love nor money. would mainly like to try and make it pick up better in lower revs ? it goes ok once wound up to 6000 rpm but it takes forever to get there almost got taken out by a vw transpoter van !!! lol.

Any info or suggestions much appreciated.