Hello,
Quite a tough brief, considering the plants need to be quite robust and able to cope with the conditions you have detailed. ‘Non-clinging’ also narrows the field.
My first suggestion might surprise you. I am always amazed at how some roses are able to cope with shade and how floriferous they can be in such hostile conditions. If you train new shoots horizontally, they will produce more flowers. Also feed the rose in late spring with a
fertilizer high in potassium and this will help the rose to flower despite the shade. Rosa ‘Danse du Feu’ and Rosa ‘New Dawn’ are both
climbing roses, well known for coping well with shady conditions.
You could also consider some of the
honeysuckles. Lonicera x heckrottii ‘Goldflame’ and Lonicera x tellmanniana will both be OK in the shade.
An unusual but interesting choice would be xFatshedera lizei, a slightly tender shrub (that should be protected from harsh frosts by the wall) It will grow 12-14 ft when trained against a wall and has the added bonus of being evergreen.
I'm sorry that I cannot help you with you question about polycarbonate panels for your greenhouse, I don't give advice on topics that I have no practical experience of myself.