ndh, sounds like you got a lemon. My seller was very upfront and listed the screen as:
7" TFT LCD Resistance touch screen
Not Retina touch screen，so don't compare with iPad
You mention buttons not working, I only have the one iPad like physical button, plus the power button. All the screen buttons carry the same TFT limitations but work for me. It also sounds like your ROM is original, if you can find a replacement ROM for your unit on the TechKnow web site (linked above) then you would absolutley get rid of any Chinese characters. Those are part of the installed ROM. Turning WiFi on and off is easy on my tablet, I gave myself an icon for it. Having it drop randomly is an indication you don't have the right driver for yours, again an issue with your ROM. The market I discovered will only show items compatible with the device. So some items may be missing. One really sweet feature I discovered is you can browse the market on a PC at https://market.android.com. Log in with the same GMail as on the tablet. You can then select to install items to the tablet and they will automatically push down to the tablet as long as the WiFi is turned on. You mention your model has 3G so that also confirms you have a different model than me.
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