Re: pricing. Not quite sure about details yet. But the high level is that 1) the design page and functionality (https://logocaster.com/logo-design/) will always be free to use and explore, 2) I'll sell one-off logos at a price point that is competitive with anything out there, 3) as you mentioned, offer a monthly option for people who want to use the tool regularly and produce logos at some moderate volume and 4) offer up the API for other interesting use cases.
Re: (4) it's quite easy to see the API in action, eg.
https://api.logocaster.com/v1/logos/new.png?action=recreate&...
Try playing with the style param (text,bubble,outlined), or letter spacing (works only with style=text).
Metadata on a logo is tucked away in the HTTP headers for the curious.