It seems that I've found a pretty useful skip. In the therum mines, I managed to clip through a rail, allowing me to drop down to a lower level, skipping an elevator sequence. The hard part will be trying to replicate it consistently (or at all). The only time I can pass through rails otherwise is when the framerate dips due to saving and you clip through(like on the normandy), or when you get knocked down by a biotic attack, and the physics rolls you under (like in the benezia fight). This time, I clipped through the rail due to framerate dips during combat, which I've never seen done before.
Edit: Okay, I think I've figured it out. There's a slight visual "skip" when you take out or put away your rifle. Done at just the right time, you can clip through railing on the left side of the last stairs before the first elevator. I've already done it a couple more times, now. I can use it to skip both elevators, and land right next to the mining laser. Unfortunately, you still need to go back up and talk to liara to trigger the enemies before you can use the laser. Although, I've notice that before the game loads the second level, the rock that you need to blast through isn't there, but the tunnel is. So, if I could find a way to jump down from the top level to right above that hole, I might be able to skip the mining laser entirely.
Edit: Okay, I think I've figured it out. There's a slight visual "skip" when you take out or put away your rifle. Done at just the right time, you can clip through railing on the left side of the last stairs before the first elevator. I've already done it a couple more times, now. I can use it to skip both elevators, and land right next to the mining laser. Unfortunately, you still need to go back up and talk to liara to trigger the enemies before you can use the laser. Although, I've notice that before the game loads the second level, the rock that you need to blast through isn't there, but the tunnel is. So, if I could find a way to jump down from the top level to right above that hole, I might be able to skip the mining laser entirely.