Regarding taxes, you're comparing two very different things. The 15% you're talking about is, as you said, qualified small business rate, which means you have [..] to hold it for more than 5 years. The 56% you're talking about in France is an over simplified number. My company just got acquired (i'm a co-founder), and I can guarantee you I got a better tax deal in France than you will ever get in the US.

I'm not even going to get into the laws debate, but just keep in mind, just like the taxes, it's not at all how you think it is :)