That's cool, but only really protects the surfer. Instead of stripping them, you could also either fill them with garbage values, or with more effort, swap the parameters with another link. This would degrade the analytics results, but might be harder to detect. And if enough people used it, you'd get some kind of herd tracking immunity.
There isn't. HTTP doesn't define a limit but browsers, servers, and other software can. A quick google search turns up multiple places referring to Internet Explorer's limit being 2,083 characters and other browsers' being tens of thousands of characters.
