Middleburn specify 28-32 ftlbs for their square taper crank bolts
OP - see if you can borrow a torque wrench to get a feel of how tight that torque is. If you mess up your crank arm or crank it will cost you more than a torque wrench
As for greasing or not greasing. Shimano supply their BB's with grease on the tapers, Phil Wood specify using grease (thin smear of course) to facilitate fit on their square BB's.
Phil Wood's BB installation instructions say:
"Clean and lightly oil the ends of the spindle, the square holes in the crankarms, and the crankarm mounting bolts. Install the crankarms securely on the spindle."
The taper on a BB spindle and crank is a press fit mechanism. The friction between the crank arm and the spindle causes the arm to slide on so far for a given amount of torque on the crank bolt. If you grease the spindle, the crank arm can slide farther onto the spindle, farther than it was designed to. The result is that the taper on the spindle forces the taper on the crank to expand. Multiple installations like this will cause the crank to move closer and closer to the BB shell, altering chainline and eventually ruining the crank when you pull the spindle all the way through the arm. BMXman
My take might be something like
steel spindle + alloy arm = no grease
steel spindle + steel arm = grease
titanium spindle + any arm = anti-seize