I'd think ores from the asteroids would be the big one.
I don't splitting water into hydrogen and oxygen and shipping this to Earth would be practical. Earth has a lot of water. Wouldn't it be cheaper to get it on Earth than to ship it from the asteroids?
There was some discussion a few years back about manufacturing processes which could be done better in a weightless environment. Some pharmaceuticals, some ideas for other things where gravity makes the product have an uneven consistency, i.e. thicker at the bottom, and this is undesirable. Nice idea, though people were hard-pressed to come up with examples that would be worth the shipping cost. Granted the bulk of the cost is getting raw materials to orbit. If you start with raw materials from asteroids, many more processes would become economically viable. If we assume that the cost of getting things into orbit has been reduced -- which is probably essential to be able to get people to these asteroid colonies -- then what's the advantage of making something at the asteroids and shipping to Earth, versus making in Earth orbit?
Sorry, I seem to be shrinking your list rather than adding to it.
The only thing I can think to add: energy from solar power. I haven't done the math, but I think that's getting pretty thin at the asteroids, so that may not be very practical either.