I started my second playthrough of ME2 using my the character from the last playthrough and it is HARD AS HELL. I'm not complaining, I know that it's called insanity for reason. My complaint is the bug that really started to show through at this difficulty. Half the time I use a power from one of my OTHER squad members and I'm behind cover, the power seems to originate from Shepard which means the attack hits the wall I'm in front of. has this happened to anyone else? Also, just wondering what everyone's strategy for insanity is. Mine is the sniper that you don't have to reload after every shot + adrenaline rush + as many headshots as it takes.

You're better off taking the Widow Sniper Rifle and using the adrenal rush with that.
 
And I've never heard of that glitch, first time I've heard of anything like it actually.

I've had that bug but I just try to work around it by always making sure shepard has a clear line of sight to the target...

I just today finished up an insane ran (S-Rank, baby) and my tactic was to hide in the first piece of cover and damn well stay there. I recommend using Miranda and Grunt- get grunts Party wide incinerate ammo to stop regeneration, and give Miranda that thing that boosts squad hp and Grunt will rarely die. 
 
And as for squad powers, they happen 'instantly', striking the enemy, no matter if they're miles away or even have a line of sight, instantly. Maybe that explains why it originates from you- because it's all done relative to Shepard. Dunno though.

One glitch that only happened on Insanity to me was that the game would switch to weird sidescroller camera.  It only happens in the middle of a fire fight and I can't take cover when it happens.  It's insanely difficult to control and usually results in me dying.

Warp ammo's pretty good. You should give warp ammo a try.

I've never had that happen.
 
As for strategy, I brought Thane and Zaeed as my party most of the time until I got Legion then I chose between Zaeed or Thane and always brought Legion.  Had everyone using sniper rifles.
 
As for my preferred weapon, as an infiltrator nothing beats the Widow.  I suspect the same is true for soldiers as well.

" You're better off taking the Widow Sniper Rifle and using the adrenal rush with that."

Insanity really is not that hard, i speed ran the last half of the game

If I'm unsure if the attack will hit or not, I do a double check by doing an attack from the radial menu. I go over the enemy, select him for the attack, deselect and select him again. It takes all of 1 second and pretty much always works for me!

Yeah it happens when yer not aiming over the cover correctly.  This happens to me on... uh.. Veteran and it just takes some getting used to.  Just be more careful where you aim.... thats all.