Dam SA can be weird and decieiving, at the time I got 1:20 it was very hard for me but when I went for 1:19 it wasn't too hard.
I think you're wasting your energy on things you think make a difference in time but they really only make you loose time.
This may sound weird but try keeping it as simple as this, strafe to the door press the button then shoot the alarm and then shoot the lock. After the lock gate just strafe until your close to the door and then just walk forward to the door and press B to open it. Don't try to do anything special to try winning time, just take time to aim for the alarm and when you have the alarm in sight then shoot. Don't panic, just make 4 shots and then back up when making the 5th and then strafe for the next alarm.
Ah crap this is just weird I have no idea if this will help at all you might just think that I think you are stupid or something but that's not what I mean. I just mean that Dam SA is simpler and easier than it might first seem, I had to really struggle to get 1:20 and 1:19 came relatively easily just because I realised something.
It is exactly what you say, you sometimes seem to get crappy runs that give as good times as a good run but that's only what you think. Try just doing the level, don't speedrun it, don't put too much effort in trying to do things fast just try to keep things simple. So like strafe press button, shoot lock, strafe to alarm, shoot alarm, strafe to next alarm and so on, stay relaxed and don't think too much about doing things fast just do things you need to do.
I know this sounds weird but maybe you'll get a PR soon, well see what happens.
