Earlier quoted context omitted.
Not to worry, but sanitizing input literally takes no more than one additional function call (at least for php/ruby/python/perl/nodejs/java/c#/ocaml). I can understand that this might be a hassle if you've written this app in COBOL, or some other word-heavy language. In which case, my most sincere condolences.
In fact I wrote this in Erlang :P
Pretty impressive, I didn't know Erlang was suitable for web programming. :-)
Nonetheless, you really should make sure that input is sanitized. XSS attacks are a nasty thing.