export wild rice to china, if there is a market for it. ?

There's a market for everything in China these days. I agree with the others though that wild rice is not currently consumed in China, but they do import a lot of rice. Mostly the imported rice comes from Thailand and that rice is a fair amount more expensive than local rice but people prefer it and it sell well no matter the extra cost.
I would suggest the market for it would be small but profitable. You would need to convince a number of fancy restaurants in Shanghai and Beijing to start serving it on the menu by selling it to them at cost but making sure they charge a lot for it so it comes off as fancy and there's your market. Hook the restaurants via there greed for a big margin and then in a couple years crank up your end.
I think it's the best way as Chinese are extremely cheap at home but like to spend a lot to impress friends and co-workers when their out, so you won't get much turn over from supermarkets. This is how the wine industry has pushed into China and it's doing very well.

Probably not because most Chinese are used to white rice, UNLESS you launch a huge campaign about the benefits of wild rice and get a few Asian celebrities to be your spokesperson. But still, your market will only be the younger generation Chinese. Older people will stay with white rice.

You should export pineapples and coconuts to Hawaii instead.

I doubt if most Chinese have ever tried wild rice, it is delicious but it's hard to get people to change old eating habits especially since wild rice is so expensive and beyond what the average Chinese would be willing to pay. Perhaps catering to the expat market would be worth exploring. I know that wild rice is not actually rice, which may or may not be beneficial since rice in Asia can be subject to strict government controls regarding imports, tariffs, subsidies and other govt. regulations. I think because of the price it may be a tough sell in China, but if it's marketed properly to the ever increasing affluent segment of the population, who knows? Good luck.

First of all, you didn't ask a question, you simply wrote an incomplete sentence and attached a question mark to the end.

Second, I would expect that grown rice and imported rice is already extremely plentiful in China.

Yes. there is.