I don't think the Anubias or Bolbitis are a very good idea for an outside tub. They probably won't survive winter. Java is much more cold tolerant but won't likely do well either. I suspect Downoi would be an abject failure. 1. Aquatic substrate? Time was that this was laterite capped with inert gravel. It still works better than active substrates, but people seem to like spending money these days. Serious plant dudes are still using laterite afaik. Potting mix is just pine bark, all organics = no good for aquaria. It rots. Use sand, gravel, clays, "loams". 2. You can do either with rhizomes but they probably won't last in the setup anyway. If you have to try mount them so you can move them back inside when they start to melt. 3. Up to you. If the plants are sub-grown when you get them you have to put them underwater or they'll die. In that case you let them start to grow out of the water and let the water level slowly drop. If you keep the substrate submerged you may have algae issues. If not you have to make sure it's not getting too dry or everything can die on you. 4. Definitely part shade. Shade on an overcast day is far brighter than the best lit aquarium you've ever seen. Don't believe me? Buy a luxmeter and go check then. 5. Yes. No. Yes. But - if it smells like a swimming pool from the tap better dechlorinate it, or sit it for a couple of days, or use rainwater = better. Weak fertiliser dude, if you're using a terrestrial one (like Aquasol for eg) then 1/4 or less than the weakest recommended rate. Should be well under 100ppm N. If you're using a clay sub then you probably don't need much or any other ferts. 6. Clay hydro balls are too big. Look at Glosso - it will struggle to get a foothold in something like that. 7. Natural daylength. Then you can observe the seasonal responses of the plants, like flowering. 8. Small containers can become algae traps. Mosses should do fine outside otherwise but will die if choked with algae. A layer of duckweed on the surface can help a lot. They'll probably be better in the existing outdoor setup as will the AR (hopefully!) and Glosso.