I can write 100 page essay about every choke point in game but that :

a) would cost of a bit of time
b) spoil game
c) be obsolete, as your own gameplay,practise and exploring is what makes game worth

I would rather point out some general advices to help your blood pressure stay calm.

Accept a fact you need to practise every single choke point in normal mode.
Accept game own rules.
Forums are full of crying babies,i would like to trust,YOU aren't one of them.
Learn metagame.
Master controls.

You must know how, when,why and what you are doing.

After heli,before Sam's rescue, there are quite few choke points involved not so much with environment,rather with Shadows random behavior.
I highly suggest you, practise this part to death in normal mode.
Check guides on Youtube,but again what you need is your own solutions,no guide will win game for you.

Actually everything is in game.
As Sam Parker said. Practise makes perfect. Always in the head Randy.Always in the head.

Game isn't optimised very well unfortunately.
Two years ago i finish whole game on slow dualcore, except NM mode.
I didn't even try to start NM.Just too many unfair deaths, due to frame skip.
On other hand, game runs fine on iGPU.

I suggest you some OC i5. :3 (What i said about dualcores still aplies today).
Fact is, you can do very little besides cpu upgrade.

old slow DC
Normal mode: playable and enjoyable,deaths aren't big deal
Nightmare Mode: No thanks, i don't want heart attack or demolish my room

"modern QC"
Normal mode: even better
Nightmare Mode:I wouldn't hesitate to do a serious NM attempt

true modern QC overclocked
Normal mode: piece of cake
Nightmare Mode:If i died it was 99% of time my own fault

You are lucky actually.We have two checkpoints in game now.
Were times when you had to play since start to end without dying.
Later with bug if you failed at Act #3 you start at beginning Act #2.(Real horror).

I consider it most valuable achievement i got.

Long distances jumps.
Did you know, there is few places in game, where, if made correctly, you don't need to pull yourself up as you already land on your feets?
They are rare,but they are there.
If you find one,send timemarks from this video guide.(They aren't there).

Nightmare Mode is worth.Remind me these old 8-bites text adventures.One mistake? We are sorry,TYPE start to start new game :)

Wish you cool mind,sure fingers. No luck needed :)