Kevko oil pickup tube tab, run it or cut it?

Yeah, unless you mount a camera in side the pan, you'll never know about any vibrations! I personally would not worry overly much about a stud versus a bolt; the record of success with studs is quite high, and if the threads are similar, the pitch is the same, and the lube (if any) is the same, then the clamp force ought to be very similar.

And FWIW (which may not be much), my one test of block distortion versus torque years ago showed that most of the distortion/movement occurred in the 1st 25-35 ft lbs of torque, or thereabouts. But it was different block type so that is purely anecdotal, and YMMV.