need to allow all characters in the URI... what should i be aware of

[eluser]plainas[/eluser]
Enabling querystrings would change the whole structure of my application.

I try to stay away from myths and paranoias as much as possible.
That doesn't mean I don't care about security.

Just so i'm sure of all the dangers out there.

Assuming all the variables used in database queries are sanitized, if i htmlspecialchars() all user data i display it shouldn't be any danger... or am i missing something in here?