How can I get Fallout 3 to run flawlessly

Good morning, afternoon, evening, wherever you are, hope your having a great day, I just bought Fallout 3: Game Of The Year Edition for PlayStation 3 as of today. I have a few questions, how can I easily get the Karma level trophies, how can I make the game run flawlessly, and how should I play the DLC content in order? I decided to buy Fallout 3 for PlayStation 3 since I already have it for PC and XBOX 360 but not PS3, I have all achievements for FO3 on 360 and wanted to go at it again and get all the trophies and a nice, shiny, clicky Platinum trophy