Editing siggy rules

I have a phpbb3 forum. Is there anyway I can change the signature settings so that members can only have text and no image?

Also, is there a way to decrease the amount of characters members are allowed to have in their sig?

Finally, is it possible to have a disable signature setting so that other members cannot see anyone sig?

Thanks.

(Please let me know if you need me to explain something better)

1) No
2) No
3) Completely disable signatures for everyone?

For the 3rd question:

I was wondering if it was possible for a member to not see anyone signature even if the user has a sig.

For example, I don't want to see anyone's signature here. So I click the disable signature viewing. Now I can't see your sig Sanket, but some one members still can.

Nah, that too isn't possible.

That's kinda disappointing...

Last question, is it possible to disable the option of uploading an avatar from another site/url.

Like members can only use avatars in the gallery.