Well, if you just use the engine to launch, or to sustain flight when there's no thermals to be found anymore, the idea has merit. Since you're only running the engine for five minutes or so on launch, and perhaps a few more to make it to an airfield at the end of the day, fuel burn, and therefore cost, will not be an issue compared to an avgas piston. So it probably comes down to engine/installation cost and weight/volume.
Will certainly strain relations with the neighbours at most airfields!
I wonder if they can still be launched conventionally (winch or tow). That would limit the noise exposure at the airfield to a great extent.
maybe there is a reason for having the canopy open on start up but I cannot think of one?
All-glass canopy with no shade whatsoever. As soon as you close it it's a greenhouse in there, particularly with no airflow to provide cooling through the vents.
I noticed the wing had to be held up on takeoff roll and the whole thing looked very unstable initially laterally.
This is normal for a glider, particularly a two-seat glider which has its mainwheel almost directly underneath the CofG.