1. hm.., where did you find the information stated that affiliates should have a website targeting US traffic? I have never heard about it. You can target any countries and any regions. I am getting sales and commission from all over the world. Furthermore, I must admit that non-US traffic is much more profitable than US traffic regarding AliExpress affiliate program.
2. There is no 2% commisson on AliExpress. The commission rate is from 3% to 50% and I really got 50% from sales several times, however most of the products are among 5%-15%. And of course I have already recieved payments from AliExpress as many other affiliates I know personally. Actually, there were some big delays in payments when the affiliate program was just launched and there were complaints about AliExpress affiliate support. But now I can assure you that everything works perfect - all payments are arrived in time every month and you can contact AliExpress support easily. Now they even have Skype: live:affiliates_79 so you can get in touch with them instantly.