ORIGINAL: A good flier and good engine man can fly with lower power. A good flier knows how to use rudder to hold the plane straight in the event of an engine out. If you read back thrugh this forum, you'll find several reports of people losing an engine and having the plane roll over and die. If you can't hold rudder in and at the same time adjust power, you need to get a sport twin that has good engine-out characteristics and learn to fly it, practicing engine out flying. Do this before you try a scale twin. It will save you a lot of grief.
Ed the situation you mention is exactly where "just the right amount of power" is critical. There is a point with only a single engine running that the airplane cannot over come the additional drag of the rudder being deflected a large amount, and the airplane will slow till it goes below VMC and spins out of control. The airplane should have enough power to climb on one engine with full rudder deflection.