I have done many Cudas and I agree the dowls are fine if they are set to the correct angle. It is easy to dial in up or down thrust and washers are needed to hold the angle over a long time. The other concept is to use a 1/4" ply and taper it on the belt sander to get the perfect angle. You can then cut out the center and the shim can be glued to the firewall to hold the position. This is no heavier than the first idea and since the shim is one piece it is easier to work with.
The cowl mount Dennis uses seems fine and I have a Cuda that is 5 seasons old and the cowl is still as it was the first flight. Understand that the cowl is long and it will move a little as you run the engine up and this is normal.
I have used the nelson system and it works great. Things to watch are - filter the paint before using viscosity is key and I adjust by spraying samples a large bore air brush works fine be sure to use a primer on his list as the paint will not like some of the primers the additive to make it flex is needed in all cases - sticks to fiberglass and ABS just fine.
My site shows some of these things in the build section
www.dream-rc-airplanes.com