Looks canny but wouldn't trust them tanks without a lid. Been keeping crab for 30 years now and the one thing i've found about keeping crab they always manage to escape.
I would watch the temprature aswell i have to keep my tanks on the floor as mid sum
mer my shed can get so warm inside the water in the tanks gets to warm, the stone floor stops cool helps stop this.
As for keeping worms use a cat litter trays and a small air stone and alway in the fridge to keep them cold and at a constant temprature, as long as the water is kept clean and any dead ones are removed they keep for 2 or 3 weeks no problem