RE: Minimum airspeed
Like Bruce says, that .061 is merely getting a hernia from trying to fly that thing.
A .15, or possibly a .25 would be more suited to the task.
I have a couple of glow powered 2 meter gliders with .15s.. but these barely get to 2 pounds AUW.
My glow powered 2M photoplanes are just about 4 pounds AUW, with modest performance.