How do I adjust the form width in QuickMode? I changed the setting in More Options, but it didn't work.

In the form's properties > Advanced tab > More Options, the form width field there only works for forms that are being displayed within an iFrame.

For a form being displayed normally, the change needs to be made to the CSS file of the form theme that you are using. For example if you have assigned the "Aqua" theme to your form, you would have to make changes to:

/media/breezingforms/themes/aqua/theme.css

Around line 43, you should see something like:

.bfQuickMode
{
     width: 100%; // here you can change the width of the form
     padding: 0px;
     margin: 0px;
}