hm i did go for beast man, high regenerate, speed and claw and finished on my first try.

it was a little short and i did not realy like the ending, well maybe the other endings are longer.

Maybe High int, high engineering, basic suit start, is just really hardcore or something?

i realy do not know, i did try nother round with time and had the ability to slow down time around me.
I could evade most attacks, but maybe the main problem is you need a lot of money for the suit to upgrade it.

Just make yourself OP.

It isn't necessarily possible to succeed in all paths in the game. Basically, success depends on the choice of powers as much as on the choices. So, if you have a low psyche you will alway get smashed by telepathic enemies, and you would do better to avoid them (or try to raise your psyche during the game, before you have to face them). For the higher difficulty levels... the game is supposed to truly be a challenge, and in many cases many of them paths are borderline impossible (I am surprised that some people are managing to succeed in them, according to the achievement list).