Power steering

If you need to steer in a hurry, a power steer car with no operating pump with be hard to steer. That could be bad..
I doubt the PS pump will use much power when going in a straight line to affect your ETs anyway.
As far as hurting the pump or box (if that's what you're worried about), don't worry, you won't.

Going straight ahead, the power steering pump absorbs about 1/4 horsepower. I know that "every little bit helps" but if you are serious about eliminating the parasitic loses from you power steering pump, you should probably install a manual gear. Otherwise, I doubt that your ET slips will ever show the difference.

The above having been said; with an additional 40+ years of experience, when I raced my new 396 1965 Impala I used to crawl under the front and remove the power steering pump belt.
JIML82