PHP GET variables

My URLs are currently way too long, so I'm thinking of using index.php as a redirect to other parts of my site. What I had in mind is www.example.com/?nigger. The thing is that I'm using free hosting (inb4 shitstorm), and I have to change hosts once in a while. Are there any server configurations (which support PHP at all) that wouldn't work with this?

>as in not assuming that it's supposed to read index.php, just given the domain and arguments like in >>4
eg. you navigate to http://www.example.com/ and the server automatically returns index.php
If you navigate to http://www.example.com/?what... Are there some servers that don't return index.php with "what" as a parameter?
Also, given http://www.example.com/a/what. Would all servers load a.php with /what as parameter, and not do something silly like looking for the directory a?
This was harder to explain than I thought. I fail.