Forms: Legacy tools - text box

Hi,
I have a form and I found it useful to use legacy tools that make it possible for text boxes to bu formatted specifically. Fine.

But there are two problems that I can't solve with that path:

1- The lenght of the "grayed" lining is short, I want it to go for a specific lenght for esthetic reasons.

2- Once the page protected for form content only, the user can still press enter once in the text box and create a lign, like it would in regular text. How can I avoid that? Regular form text box don't do that...


Anyone savy?