I ran into almost all of the problems you mentioned, except for the cowl issue. Don't know why, but mine fit perfectly using the supplied dimensions. When I mounted the engine, I put the cowl on and measured thedistance from the firewall to the front of the cowl. Then I marked the mount forthe engine so that the thrust washer was about 1/8" longer. The distance from the top of the firewall was correct. I screwed up when moving it for the offset because I measured from the CENTER of the beam instead of the edge. The nice thing about the 1.60 is that it fits completely within the cowl. The only holes I had to cut were a small circle for the plug, needle valve, and a 2" square in the bottom for the muffler extensions.

With the OS 1.60, elevator servos mounted in the tail, rudder srevo mounted just behind the wing tube, I added 12oz of weight to the bottom of the engine box to balance. If you do the math, there's about a 3.5-1 ratio from CG to tail and CG to front. If I move the servos to the wing compartment, I can probably eliminate all nose weight.

But, this thing is a great flyer. I wouldn't hesitate to buy another Creek plane, given the chance. With the things I learned on this one, the next one would go a lot smoother.