With a safety razor, you don't have any control over the blade angle.

Everything else you said in your post gets a big +1 from me. However, this is just incorrect. You have almost as much control over the blade angle as with a straight. Lifting the handle more or less in relation to your face changes the angle of attack. General rules of angles for ATG, XTG, WTG still apply.

And one more time for good measure:

Don't compensate with more pressure!