(Warhammer 40k) How do you fight for the Imperium?

Are you a Space Marine, An Imperial Guardsman, or part of the Adeptus Mechanicus?

1 You see a heavily defended enemy position. How do you take it out?
2 Orks are attacking, what do you do?!
3 What do you dream of?
4 What is your favoured weapon?
5 The God-Emperor has arrisen again!