Is it possible to LOCK text in place, BUT keep the words editable?

I'm looking to allow customers to add text to a banner. I want to lock the logo and text in place, so that the customers cannot move them, BUT I want the customers to be able to edit what the text says. If the customers alter the layout, the layout will no longer comply with my client's approved design. The text must go under the logo; I don't want the customers to be able to move the placement of the text.

I see that layers can currently be locked and unlocked, but I want to be able to lock them on the admin side so that customers cannot unlock them. Is that currently possible?

If so, is it possible to lock the text in place, but keep the text editable?

I appreciate any and all advice.