Re: Interesting idea
"A large part of the reason the renminbi can't compete with the dollar on the international stage is that it's pretty much illegal to take it out of the country."
Not quite, you can take out up to 20,000RMB (equivalent to about £2,300) in cash legally from China. I know this this 'cos I regularly do it and have been doing so for several years.
Any high street bank will happily accept it.
You are correct about government regulations though, Bank transfers are quite difficult though but for savvy old China-hands it's possible.