I haven't seen a disclaimer on a stack exchange site before; but a lot of the answers given on this site could constitute "professional advice", although I doubt anyone would intend them as such.

Would it be a good idea to add a catch-all disclaimer to the footer of the site to clarify this position?

Something like:

> 
> Disclaimer : The information on this website does not necessarily
>  reflect the views and opinions of any associated companies. Neither
>  should any suggestions or advice contained on this website be relied
>  upon in place of professional advice. You are responsible for checking
>  the accuracy of relevant facts and opinions given on this website
>  before entering into any commitment based upon them.
> 
> 
>