You'll have to be a little more specific about the roll-out problem. Is it pulling left or right or just nosing over? One solution to nosing over might be to install a nose-gear like the pictures in post 302. It could still operate as a taildragger, but the nose gear would just prevent over-rotating onto its nose. Remove the nose-gear once you get proficient. Think of it as a "training wheel." Touching down with the stock wire gear and the pants installed at too fast a speed has caused nose-overs for me. Three-pointing is the best way to avoid that. The aircraft must fly slowly to be at the increased angle of attack required for the tail wheel and the mains to touch down at the same time. This means that the gear are rotated further out in front of the C.G. for any given descent angle and the lower speed puts less bending forces on the wire gear that might cause the wheel to contact the inside of the pants. Just flying without the pants installed until you can three-point your landings consistently might do the trick also.

Rudder control hasn't been a problem for me. In fact I find the rudder control very good on my G.B. I have my push-rod connected to the innermost hole on the rudder control horn and the outermost hole on a four holed servo arm. I may also have mixed in more than 100% throw for the rudder servo to allow the rudder to move to its fullest deflection possible. Did you use the shrink tubing on the rudder and elevator push-rod? I didn't think that would be sturdy enough, so I used carbon fiber tow instead.