Is my covered plant rack viable as a mini greenhouse?

OK, so I've got a plant rack set up on the side of my house. It's covered by see thru roof and at the sides and back with thick transparent plastic. The reason is to prevent the plants inside from getting splashed by rain. I'm planting potted figs there so exposure to too much rain causes leaf rust which is bad for figs.

The 1st pic is the latest modification. I plan to close the front with 2 double doors (pic 2). These doors will be covered by greenhouse mesh so air can circulate in the rack somehow.

I've got a rain collection setup; you can see the grey gutter, and water flows into the 160L blue barrel (with black cover, gonna upgrade with the bigger 270L barrel beside it). There's also an auto irrigation system; it pumps water from the blue barrel to the pots every morning; you can see the smaller capillary tubes. I set these up because watering all the plants every morning is an absolute chore.

Some questions:
1. Will the temp become too hot if I install the doors? I'm thinking of setting up a cooling system but not sure if it's necessary.

1. How to choose different time setting for selected plant? Right now all plants got sprinkled with clean water for 1 minute ever day. Each plant got its own fertiliser.

2. Is this setup good enough? What other things I should consider?