First off to get geth weapons you will have to become a spectre and you need to be high level I'm 44 you need to be at least level 42 to get a "Geth pulse rifle" You can get the VIII version of the rifle by killing geth.

"This may take a while." You can also buy a geth weapons permit later on in the game for around 27000 credits I paid over 550,000 credits for a GPR 5 they are very rare and expensive and sell for good prices and are very accurate.

And to make your machine gun never overheat you need a top of the line rifle. "A VIII model will do." Now you need two high level heat reducting parts and any ammo type you want. "As long as it isnt exploding rounds!" Now you should be able to kill a whole unit of people without taking your finger off the trigger!

Heres a glitch that can only be done after you beat the game and start over. "Make sure you start with your saved game data!" Don't start a totally new game or it wont work. Early on on eden prime after all the movies are done and your free to move around with kaiden and jenkins."The one that gets killed." pull up your equipment screen and you will be able to equipt Jenkins with any type of armor even alien armor! "But his appearance wont change :( you can even bring him up to your current level but he still gets killed.

and by the way each character will have a clone of the weapon,Armor etc that they were wearing when you beat the game in your inventory <3

After a few of the main missions, if you go to the Citadel there will be an interviewer. (She is there as soon as you leave the docking bay elevator with a robot camera thing) She'll ask to interview you. Accept and answer the questions until she asks about the Normandy. Click the bottom right choice and shepard will punch her in the face. Then she curses at you and says your career is over. I thought it was kinda funny.