Human Habitats in space

I suppose there are several million considerations. Two+ tests on Earth indicated that we can make some of the oxygen needed from algae and other green plants. We need to invent the material from which the giant bubbles will be blown. One ton of an oxygen/nitrogen mixture may be enough to blow hundreds of bubbles as the pressure outside the bubbles is essentially zero. A means to make the bubbles strong is needed to allow them to be cut and assembled. A further strengthening is needed after assembly. The material needs to let most of the light useful for photosynthesis in, without letting air escape. We have not done large scale photosynthesis experiments in space because the material is not available and may never be.
Approximately zero gravity relative to the habitat is called free fall. There is some evidence free fall is unhealthy, but we have not exhausted the possibilities. We may end up accepting that colonists are un-healthy and will be cripples if they return to Earth. Artificial gravity makes photosynthesis more difficult and docking and communication and astronomy etc. If it is done by a tether between two habitats, failure of the tether is dangerous. Please comment, embellish, and/or refute. Neil