[meeera]

(Why did you put "kindle paperwhite" into your profile as your device, if you have a Kobo Aura HD? Odd.)

Are you looking for workarounds, or something else? Perhaps you should sell it and buy a Kindle.

Meanwhile, you can buy your books from anywhere that sells ADE or non-DRM epubs, you're not locked in to the Kobo store. If you buy from Amazon, you'll need to strip any DRM, then convert the format with Calibre; I don't know if there are any pitfalls doing this with Chinese books, but it works perfectly for all of the English books I've come across.

There are a number of ways to get books onto your Kobo. You can simply drag and drop them from your computer when connected with the cable, you can add them with ADE or Calibre, you can put your book on a cloud service and download it from there, or you can use the Calibre Content Server to transfer them wirelessly.