I am very concerned about responses I got from 回国发展

I am very concerned because I got some other responses from 回国发展 as shown below.  

回国发展 http://bbs.wenxuecity.com/backhome/542462.html

not all ATM machines in China would take your bankcard

回国发展 http://bbs.wenxuecity.com/backhome/542462.html

Master/visa card may not work. Even if they work by luck, the processing fee is high.

回国发展 http://bbs.wenxuecity.com/backhome/542458.html

For iphone3G and maybe 3Gs, you may buy a Chinese sim card. For iphone4G, unlock is difficult and with lots of steps to take. Also, the sim card in iphone is smaller, and they need somebody in the cellphone store to cut it for them.

In a nutshell, your ATT iphone won't work in China even with a Chinese sim card.