RE: WINGSPAN AND WING ROOT TO PRODUCE LIFT AT WHAT SPEED WITH A WEIGHT OF
Speed lover, your idea for decreasing the float is flawed. It's not having a thin wing that reduces the float. It's from the airfoil's camber amount and the wing loading. For the style of model you're talking about the airfoil would have a relatively thin airfoil anyway so that isn't a real avenue regardless. The other factor is wing loading. If you make the loading high enough it may slow down the float on landing but mostly it'll just make it so the model has to fly faster to stay in the air and make it harder to land.
Besides I've seen lots of references to the formula 1 racers with thin wings and higher loadings float on landing due to how clean and efficient they fly.
Truly the only two ways to steepen the glide slope for landings are to use flaps or airbrakes and to learn to fly the model more like a real plane. In full sized aviation no pilot that wants to survive long would EVER dive their craft in for a landing like us model guys do. They set up a slow nose up attitude way out and use the drag from the near stall flight to help establish the glide slope. Combine that with some flaps or other drag device and even a lightly loaded slow flying model will settle in very predictably.