The only trick with changing widths is that you need to make sure to adjust your column widths and form element widths so that they fit inside the form you have shrunk.
Once you get the settings correct you can save as a preset and use it again.
You can always hand edit the forms once created as well, don't forget you are using DW and it has the ability to manipulate CSS on completed pages. Editing by hand after the form builder is completed is a perfectly viable option.
Did this help? Tips are appreciated...
