Two hoop house questions

I'm building a hoop house to replace my current one; the problem was that my current house was too low and didn't vent properly.

I have automatic openers currently attached to little square vents. Hanging these from the hoops was difficult, bowed the structure, and didn't vent efficiently.

There will be a door at both ends. What if I somehow attached the openers to the doors? I would need a spring to keep the door shut when the openers were closed, and a chain to absorb the shock of the wind before the opener gets smashed.

How could I make these things easy to remove and replace so that I could enter?

Secondly, could I just attach the plastic with ropes run back and forth over the structure, similarly to how smaller hoop tunnels are held down? Our hoop low tunnel has stood up to some intense winds with just ropes running to rebar pins holding it down. I'm thinking that I would use quite a few cross members on the hoops, and then use strong cord of some sort with tensioning straps, two crossing each bay of the structure. Good idea, bad idea, or totally crazy idea? I want to be able to easily uncover it, and digging up plastic is not doable on a frequent basis. Also, I could then push or fold the plastic up to vent the structure in the summer.

Is it possible to install your vents above the doors? I would think there is enough rigid structure from the door frame to work off of. That way you don't have to fuss with springs that aren't strong enough or not too strong, preventing the openers from functioning properly, and you won't have to remove anything to enter the structure.

I could; but I'm not sure if there would be enough surface area there. We will see.