I currently use a third party add on for this.
In order to change anything in this, I have to make changes through the languages translations part of the admin area.
I would really like to be able to use a wysiwyg editor to edit and create a "Terms & Conditions" as a page.
This would make it easier and give more options to use colors, fonts etc.
Is this un heard of ?
Why don't you use a general online editor and simply store the resulting html as a static page. I.e. in the document root of your store. I.e. t_and_c.html or better yet, make it a PDF file that customer can then simply download to review.
Make sure that you edit all data for terms-containing variables in the language translations. Just search for "terms". Copy the text in a normal HTML editor, change to WYSIWIG, edit the text, change back to html and paste it in the language data field. Save and edit the next field.
Depending on your CS-Cart edition, create one or two separate pages with Terms & Conditions - one for the Customers and another one for the Vendors; put them in the foot links under Customers and Vendors for inspection.