Well any individual can accept payments to their phone of course. But to actually have like some kind of store front on WeChat you need a "Public Account" as stated in the article.

Companies that are not registered in China can open one no problem, but only people using the English version will be able to see/access your "Public Account".

If you want to sell to Chinese people, you will need to register a Company in China. Of course there are ways around this, there always is in China.

Really depends on your strategy and what you are selling, some foreigners selling products here, just create a separate regular account to keep their buyers/followers updated on latest news/products, and talk directly on wechat to accept payment.

Any questions bartnanka at gmail