Diagram editing is a function of EA Application, however to make it easy for process modellers to edit diagram from Proalborate we have introduced the edit using EA SaaS feature, please refer to the Video
Prolaborate allows anonymous access to model information (read-only, community edition), but in this the user won't login, rather just view a diagram or an element shared by link (similar to share as a public link)
you can get an link to the image using webea too, but there is more to it than just sharing as an image, for example if you intend to let the users interact with the image and look at the details that you've modelled (such as notes, attributes, tagged values, connectors, etc) you need the simplification and curation that Prolaborate offers.
At the moment the reviews and discussions are persistent in Prolaborate, and any review that is complete will be Archived (not deleted) , this is important as many organizations use Prolaborate review feedback as an evidence for changes in projects or models.
It is not possible to create connected items in Jira from EA out of the box. But, as we said critical requirements can be implemented with the help of our teams. You can either connect with your local Sparx Services team or drop an email.