As of this writing, I'm stuck at the beginning of the Collectors' ship portion of the game.  I'm having trouble getting my allies and myself into a good piece of cover, leaving me shit out of luck against Harbinger.  I'm playing on Hardcore, so I've been using Miranda in all of my missions due to her Warp and Overload abilities (you'll need those skills throughout your playthrough if you want less headache).  No matter who I use, I can't get much help out of them.   
That would be OK if I wasn't probably the worst class for Hardcore and Insanity: Vanguard.  I have powers like Charge and Shockwave(?), which usually get me out of cover for long periods of time, ultimately getting me killed in the process.  I think if I had better powers like Adrenaline Boost, I'd be able to get a few shots off at Harbinger.  However, that would mean starting the entire game over again to choose the Soldier class.  That would be a bit hard to do, since the game I'm playing now is my second time through the game with an imported character from ME1. 
 
So, I ask you, fellow Bombers, what should I do at this point of the game?  

Lower the difficulty.

make a sandwich

I played Insanity/Vanguard 
 
Do you have a special ability? What is it? Reave is great because it hurts enemies even if they have a sheild/barrier/armor up. It is good to use freeze ammo because once they are frozen, they can't shoot and get double damage. For that mission, I'd Mordin and Miranda, or Thane and Miranda, he also has warp and his sniper rifle both great against flesh enemies. I rarely used my charge ability, mostly I reaved a person warp them with my squadmates and they get enough shots on them to freeze them letting me finish them off. 
 
Also if you level up anything to the full use the ones that go for squad ammo or wide range

" Lower the difficulty. "

Uhh as a side to this thread, can anyone link the chart that spells out what's needed for everyone to live?  I looked for a bit but have failed so far at locating it.  

" Uhh as a side to this thread, can anyone link the chart that spells out what's needed for everyone to live?  I looked for a bit but have failed so far at locating it.   "

" Uhh as a side to this thread, can anyone link the chart that spells out what's needed for everyone to live?  I looked for a bit but have failed so far at locating it.   "

i play on Easy.. i cant take the pressure anymore, so fuck it

I don't know how locked in you are with your current play through, but here are some things to consider that might help play a better Vanguard (atleast from my experiences): 
 
-Charge just isn't necessary. You're relying on cover during harder difficulties, but Charge leaves you completely open unless you use it when there's only 1 or 2 weak enemies left on screen, most of the time you don't need biotics at that point. 
- Vanguard can get shot up easily, so as my additional skill I found a shield skill (I think I used Jacob's) very useful. Activate the shield before combat, then whenever the enemy burns through it just use the skill again for even more shield.
- Cryo ammo at rank 4 was awesome. You can give freeze ammo to your entire squad, use that, combined with 1-2 area of effect biotic/tech skills, and it works wonders for crowd control. 
- Shockwave was my go-to biotic skill right from the start. Shockwave can pass through cover so you don't need to be in the open, and neither does your target(s). Rank it up. 
- Miranda was a staple squad member, I maxed out Overload as an AOE and maxed out Cerberus Officer for the squad bonuses to Health & Weapon Damage (bonus is passive and active even if she falls in battle). 
 
Finally, it's worth getting a better SMG as quickly as possible. Get these from the Tali and/or Kasumi missions.

Solider is really the only way to play Mass Effect 2, especially on harder difficulties. It's just the unfortunate truth.

"Solider is really the only way to play Mass Effect 2, especially on harder difficulties. It's just the unfortunate truth. "

I just completed a hardcore run with my Vanguard, and here is some the best advice that I have: 
 

• Always be Charging. Charging is how the Vanguard recharges its barriers, and Heavy Charge temporarily slows down time tike adrenaline rush. I was almost never in cover while playing a Vanguard, even on higher difficulties. That said you need to know who to charge and when. Try not charge Harbinger or a YMIR mech while its surrounded by enemies. Always go for the slightly more isolated enemies, especially those that you can kill in one or two shots.
• Ditch Shockwave. Shockwave is widely regarded as the worst biotic power in the entire game. On higher difficulties its practically useless with the enemies all having shields/armor/barriers. At most put in enough points to get access to pull.
• Get squad-mate cryo ammo. This is a life-saver right here. You're squad-mates are rarely going to be the ones putting enemies down, but with this they'll be leaving behind plenty of frozen enemies for you to pick off.
• I didn't really use bonus powers that much, but the best option for a vanguard would either be Reave or stasis. Reave is good at stripping barriers and armor, has no casting time, and if the enemy is unprotected it will stun them and heal you. Stasis is good for taking a more powerful enemy like Harbinger out of the fight while you pick off the weaker enemies.

Charge refills your shields a bit right?
I only use it if I'm sure it will kill the enemy, there's cover nearby and I won't die in the process.
 
Fortification/any other shield boost is great, be sure to spam your squads moves as much as you can and a good heavy weapon (Arc Projector, Particle Beam) for Harbinger if he's being a dick.

The Arc Projector is very helpfull. Especially against the mass Husks later...

• almost have never used Charge up to this point; leveled up Shockwave all the way
• never bothered with Pull, since I thought it was ultimately useless when I used Jacob
• have Team Armor Piercing Ammo and Team Cryo Ammo
• as stated in my first post, Miranda has full Overload and Warp (I thank the Beer Baron for that one)
• Mordin has full Incinerate
• I use the Eviscerator shotgun, since it seems to be my strongest
• I always tend to use a sniper rifle, though 

You did something very wrong when you decided not to pick Soldier.

Um, guys?  You know when I said I was pretty boned while playing ME2?  Well... 
Can you guys say E 74? 
 
Yeah, just got the message today when trying to play some Bioshock 2.  I guess this is an opportune time to get a 360 slim/Kinect combo whenever I get the chance.  Until then, I think I'll be playing some PS3 and PS2 for a while. 

I beat it on insanity on first play-through with soldier.