Here is some help for Raze, I can help you on every level on the Human campaign except the Final One. If you need more help ask troopdude, you can find him as one of my friends. Anyway just ask if you need any help.
Here is my weapon ranking, I put shotgun low because you have to get really close to use it. I put Assault rifle higher because it is automatic,same with chaingun.
This is a great sniping spot pointed out to me my by friend troopdude, another good one on stranded is on the left of the ship there is a place with a shield. When people come shoot them with either rocket, sniper rifle or chaingun. But here is the main sniping spot.
Snipe Mount. i got a unstoppable combo. 35 kills in a row. ok. here we go. you have to do sniper rifles only. then, got to the place, "stranded." you know where the first aid is, yeah, that's also one of the places where you come back to life. there is a platform above that place. (not outside the ship though.) kneel down, and you'll see a wire in the background. put your mouse on that spot. every time someone dies and goes there, shoot. you'll kill them instantly if you do easiest. (it's a good way to earn BOOM! headshot the trophy.) find as many rifles as you can at first, so you don't have to look for them while your getting your giganto combo.
this is MY ranking. let's not make this a big debate/argument, (this happened in my forum) ok? 1.rocket launcher 2.sniper rifle 3.grenade launcher 4.assault rifle 5.zapper 6.railgun 7.shotgun 8.chaingun 9.uzi 10.magnum T2
Yes, in the stranded place on the left side of the ship there is a shield and sort of a grotto. Hide there with a sniper rifle,assault rifle, railgun,rocket launcher etc... just basically long range weapons. Camp there and when people come by, make them go boom! And stay crouched so that you have better accuracy.
here is another place to get combos... this is what i call back stab. again, you must go to stranded. to the first aid/respawn area. (like snipe mount) players:9 difficulty:easiest weapons:assault rifle now, instead of mounting on the snipe mt, go behind the first-aid. players respawn and you shoot them in the back multiple times resulting in death.
If there is anyone who needs help name the place eg: Stranded,Plant,VR, etc.. and the type of match eg:Juggernaut,deathmatch,team elimination etc... I can help you anywhere.