change ‘create new blog’

You can change the next of the “Save & Return” button with the parameter: frontier_return_text

And the link text with:

frontier_add_link_text
Replaces the “Add new post” text on the list form – Example: frontier_add_link_text=”Add new thing”.

shortcode parameters can be found here: http://wpfrontier.com/frontier-post-shortcodes/