Opinions vary by quite a lot on washing, but I use 20 minutes, without hypo clear.
To expand your tank collection, these food canisters work very well with 4x5 single sheet hangers, they are readily available from kitchen stuff stores; http://www.oxo.com/p-442-pop-contain...-15-quart.aspx
Note that these "tanks" are shorter than the hangers by 1/8 inch or so, thus the hangers don't actually hang at the edges, but they are a good fit in all other respects. Plus you get a sealed lid if you want it.
That's a good idea, i'll look for plastic re-usable cereal boxes that might fit my 8x10 hangers.
If this is anything like the Kodak xray stuff I have played with, it is coated on both sides, so yes, hangers are better than tubes, which will not guarantee chemistry reaches both sides.
Oddles of silver in the stuff so your fixer will exhaust faster than with conventional film products
Fuji HRT has emulsions on both sides. So I'd imagine it will exhaust my fix faster. But fix is still cheaper than film ;)