What are you attemping to accomplish? What material are you drilling into, and for what purpose? Most homeowner do-it-yourself projects are not critical as far as speed or torque for drilling holes. I have a Dewalt cordless drill, 14V, that I used on "high" speed for wood and metal drilling.
For screwing, same thing applies. I lock the slip clutch on my Dewalt in the "locked" position. The key to not overtightening is experience and being careful. A good practice is to use your power tools to get the screw close to tight, then hand tighten the last turn or so. This will prevent stripping threads in the wood.
Anyway that's a start. Need more info on what project you are working on.
If you are running a professional woodshop to make money, you need to get into the details. The comments I made are catered toward the homeowner/do-it-youselfer.