Your questions are fair.
Regarding installation of the full version of the plugin, we use PDFTK to dynamically fill PDF files, so if you want to install 100% of the service onto your server, your server must have PDFTK installed, PHP shell commands enabled, and the intranet version of the plugin.
Regarding our company, while we are new to offering the plugin to the public, the plugin itself is not new as it has been used in several businesses for years, including the 12-year-old insurance agency owned by the owner of this company.
At this point of five full months old, the plugin has more than enough users to sustain the service indefinitely. Feel free to use the plugin and the service or just the plugin and install the entire service on your server now or anytime in the future.
We remain at your service.