[tim333]

I learnt to fly in a 150. Yeah you can't tell exactly where the balance is from a picture and it depends where you've put the luggage and so on.

Edit: Pausing the video at 32s it seems he's pulled back on the stick and managed to lift the front wheel a few inches https://youtu.be/1dLAmhDWEE8

[topspin]

He fully deflected the elevator and bounced the nose gear. With zero passengers. You put 6 adults and a co-pilot forward of the rear gear and I bet even bouncing will be out of the question. But we don't know if the ground speed was even representative of take off, so we're all just guessing here. With regard to cooling you can see an evolution here in the BBC photos: the first two images show no cooling ducts on either side of the TAC-003 engine compartment, but later images show several. I think geff82 is probably spot on about the design.