Feature request : Better functionality for customers (portal users)

I would like to put in a feature request for consideration. We use Jira Service Desk for all incoming requests across Digital, Marketing and IT services. We find for Digital/Marketing related requests there is a lot of back and forth with the user required which we ideally would like to keep within Jira and not revert to email. This is difficult to do when the functionality for the end user/requestor/portal user is so limited. This is also making it hard for us to continue to get buy in with the organisation so they can trust once they've logged their request they can also continue to work on it with the teams, provide feedback, review versions etc..

We obviously don't want to give all staff access to Service Desk licenses either, which would solve a lot of our issues, but we would like more functionality to be considered for the end user portal area / requestors.

Some issues/ideas are: 

1. End user facing KANBAN board - It would be ideal if we could have an end user facing KANBAN board of selected issues/types. This would provide the organisation visibility of the volume of requests in a queue at a given time, and to see in a KANBAN style where their ticket is in relation to others. Users could interact with this board in more ways than they can currently with the End User Portal way of checking the status of a request. 
2. Ability for requestors to @ people from the customer portal -  When checking the status of their request and adding more content, only the assignee of the ticket is notified. Being able to @ someone would allow for better communication.
3. Allow end users to see sub tasks or linked issues in the customer portal - End users cannot see sub-tasks or how Linked Issues are set up in relation to their main request. For example, we will receive a main request where we keep all the core info required to deliver. We'd ideally use sub-tasks to coordinate related tasks but cannot because the end user can't see those, only SD users can. So we use Linked Issues but this just creates a wall of new tickets for the end user in the customer portal, where us SD users can see that they are all linked together making it a useful feature. A better way to display/categorise Issues and Linked Issues in the customer portal would be amazing. 
4. Consider a different user type for Jira SD such as 'collaborator' -  Ideally we would allow some core end users to have full Jira functionality but we don't because we can't have them accessing other tickets not related to theirs, or seeing internal comments. Perhaps another user type could be created that allows an end user only to have full Jira SD access to a single Issue or request type. We could perhaps select a status for a ticket such as "In collaboration" which then allows it to be visible in full by the end user for that period or a user could be a 'collaborator' which provides them more visibility of their request but no access to other areas of Jira.

These are just some initial observations!