Before I start - this feedback is trying to ensure that a rounded discussion occurs; not simply to poo-poo other's comments.
What point is there in offering legal advice if you're then going to disclaim it all?
If you offer this advice and whichthen proves to be flawed and costs your client money, then I'd expect to see them in court. And I somehow doubt any professional indemnity insurance you may or may not have will cover you for this... is the couple of hundred quid they paid you for the advice worth it?
Living life on the edge is fine - but only if you have no regard for the modern ways of business; lawsuits aren't restricted to people tripping on pavements or those involved in a motor accident.
One other point; if a solicitor started offering web design consultation we'd be peeved. If you're going to claim to offer a professional service then just maybe you should consider being as described? Do you also offer to help your clients with their accounting and investments? The bottom line is - if your client wants something legally binding and in sympathy with their business then that's what solicitors are for.