I believe you diagnosed your problem correctly. When you get up on step, the negative incidence in the bottoms of the floats is letting the plane rock over onto the noses of the floats. It's like trying to push a wheelbarrow really fast.

It is conventional to set the plan up relative to the tops of the floats, but the real parameter of interest is the planing angle of the bottoms and yours is off. Actually your "free" floats have been pretty expensive........

Also, just additional information: the incidence of an Eagle wing is about 1 1/2 degrees positive from the bottom....the chord line is measured from the most forward edge of the dowel to the center of the trailing edge.

Somebody already threw you a link to my website: I don't sell anything but I threw several links on there where to get good, foam-cored floats. It has been reported that RNZ is no longer operational but the website is still up. Plane Fun Floats and Seaplane Supply are both good choices.

Oh, and don't blame the motor for inadequate power to perform inverted maneuvers: it's the Eagle airfoil. The almost sharp leading edge is the culprit. I had an Eaglet50 (same, just smaller) and tried everything to get an outside loop, including terminal-speed dives for airspeed. All I could get was level inverted flight regardless of the position of the stick. With a good set of floats I generally notice IMPROVED inverted performance.