Any control serface has a gap between it and the fixed surface. Air gets in there and does some strange things. If you seal the gap, the air on top stays on top and the control serface works better and it cuts down on flutter. I seal mine with hings tape. It's clear and goes over any serface and you don't need to iron it down, just use a peice of balsa or something to put some pressure on it to seal it good. I do that on the bottom of each control serface and the rudder I do one side. Just bend the control serface as far as it will go and then put the tape or whatever on and press it in place. If you use covering material, you will have to iron it in place, but if you use hinge tape, just press it down good and cut off the part that comes out of the gap or lay in down on the stab and elevator or whatever control serface you are doing. It really does help and is a good idea to do it on all your planes.

Your still going to have to worry about prop clearence on a tail dragger. It's not as bad as a tri gear plane, but you will still have to watch it a little. Put the center line of the wheels at about the leading edge of the wing and you should not have any problems with handeling. You can go a little ahead of the leading edge, but don't go behind it. If you do, it starts getting squarlly and hard to handle. I made a Kaos into a tail dragger and it works great. I just put the landing gear in front of the wing mounted on the fuse as close as I could get it to the wing and it handels great. Goes stright as an arrow on take off and landing and doesn't do anything stupid. If your prop is to long though, you will not be able to get the plane in a level attatude and you will have to take off and land nose high. That is why you have to watch you prop clearence. You could go to a 3 bladed prop to help this, but you are limited in the prop selection with 3 blades. You could always go smaller dia and more pitch, but that will give you more speed, so you will have to watch the throttle more then with a flatter pitch.
Ed