Wanted: Torque wrench for cranks and what tension for Sugino 75

I have slightly greased the tapers before, never had a problem, but stopped doing it out of pure fear :)

Start doing it again out of well-founded fear.

Question on Torque Wrenches:
Are they really necessary?

Yes, but more necessary for some things than for others. Stuff used to be massively over built, and you could get away with just leaning on the spanner. Now things are more refined and the margin between tight enough to hold and so tight that it breaks is far too small to judge by feel.