Fórum podpory Firefox

I have different login forms on different sub domains so I always get a huge lists of different logins. and also I get my password for the basic auth from the web-server on my login form.

I also consider this as a security risk when different sub domains belong to different parties and I accidentally put my password into the wrong form.

Can I config Firefox the way that I get only passwords in the list that match the exact url or at least the (sub)domain?

Another Question As a Web-developer can I do something that my client don't experience such a mess (like giving the login form a special id so passwords are restricted do this particular form.