I have the Tower hobbies Uproar which is nearly identical to the Dazzler except for the omission of the turtle deck. The OS 46FX with a 12.25x3.75 APC is the best combination for this plane, IMHO. Yes the FX weighs slightly more than the LA, but it makes much more power and is a better all around engine design, hence the $48.00 increase in price. To me the extra cost is more than justified by the performance gain and longevity if properly cared for. Another good engine for this plane would be the Thunder Tiger 46 which is a little less expensive, but a good engine none the less.

If you have already mastered your Easysport I think you will have no problem flying the Dazzler, if that is a concern. It's an easy flier. The Dazzler is a tail-dragger, but should not pose much of a problem compared to the Easysport because it doesn't stay on the ground long on take-off.

As far as building goes, there is not a lot of plywood in the kit and it builds light per the plan, so personally I think it's overkill to replace it with balsa laminated with fiberglass as you suggested.

I enlarged the control surfaces on mine and added counterbalances to the elevator and rudder, while making the horizontal and vertical stabilizers 1/2" smaller across the chord of each. I didn't like the way the vertical stabilizer was mounted either, so I mocked the mounting of my GP Cap 232 vertical fin. The one thing I would recommend is to not drill your engine mount until you have the plane complete. This way you can adjust your CG by moving the engine for or aft as needed.

Have fun!