Might some things break because header information or content is being altered?
Definitely. More and more sites use HTTP header content to decide what to display and how to display it. There is many ways that this can be handled, so having hard and fast rules, is tricky. “User-Agent” in particular is often used in this way to identify the browser, and adjust content accordingly. Changing this now (at least not further than removing the OS information) is not recommended, since so many sites do look for it. You may get undesirable results by changing this. For instance, different browsers use different encodings of Russian and Czech characters, certain web servers convert pages on-the-fly according to the User Agent header. Giving a “User Agent” with the wrong operating system or browser manufacturer causes some sites in these languages to be garbled; Surfers to Eastern European sites should change it to something closer. And then some page access counters work by looking at the “Referer” header; they may fail or break if unavailable. The weather maps of Intellicas
