I can only assume that the 3/16" blade is necessary for scrolling curves and not ripping boards into thinner stock. For curves with a 3/16" blade, modifying speed or torque will give you nothing. A 3/16" blade is flimsy to start with. Tooth configuration will have some impact on performance, but sharpness will have the most impact. A dull blade is not your friend.
Have you gotten a copy of Louis Ittura's catalogue? He covers this in depth, including what pulley sizes to use to achieve best results. As for lubricant, the set in the teeth opens a kerf wider than the body of the blade, so lubricant isn't necessary. FYI, band saw blade speeds are measurd in feet per minute, not RPM's