[russ2020]

In my previous roles, I was the Scrum Master. For those unfamiliar with Agile, below is a description of each of the Team roles.

Product Owner (PO)
Often the PO has dual roles in Agile Teams, being accountable for work being completed to a certain standard/quality, they are sometimes the Team's line manager in organisations. They will also directly report to middle and senior management for this reason. They may also belong to the Business department and have been given a special responsibility to deliver a solution to a specific problem. POs may also do this Role for multiple Teams (1x PO shared across many Teams) which can also cause issues. POs need to know their Users, the Business they represent but also be able to talk to the Business about what the Team can/cannot do for solutions and advise the Business about where the Product can go. 

Developers
Also known as Engineers (e.g. DevOps Teams) and include organisational roles such as Architects, Designers and Solution Designers, the Developers "do" the work to complete User Stories, Features and Epics. They will work together to understand the requirements from the Stories, create the solution to build, test and implement, do the actual work and then demonstrate how it meets the requirements to the PO.
I have seen many different variations of responsibilities for the Developers in the Team, the most mature will take a Story and run with it through creating solutions, doing Spikes (investigations) and whatever they need to complete the requirement from the Business. Other Teams may not do the solution but instead will receive one as part of the Story, build, test and implement and hand it over for presentation and Productionisation.

Scrum Master (SM)
Some resources state that the Scrum Master is akin to the glue between Team members and between the Team and external Teams/stakeholders. From my experience, it's some of this but really its about the concept of Servant Leader. The Leader part is self explanatory, and for recently formed Team, the SM will bring everyone together, build a good report with the Team and between Team members and allow the Team to get on with the job of delivering solutions. Later, the SM will help shield the Team from external influences that distract them (sometimes called noise), in which case the Team is often happy for the SM to talk to other Teams on their behalf and facilitate discussions as required. The power behind mature Agile Teams is where the Team itself operates cohesively, collaborating seamlessly, they each know what everyone else is doing or there is full trust within the Team that when they take on a task it will be completed or else the whole Team is told if they need to jump in to help. Teams can operate without a SM, however someone or the whole Team will share responsibilities that a SM has. In my experience, it eventually leads to a SM being brought back in so the Team can concentrate on their other tasks at hand.

[Genesis]

@russ2020 I'm not sure what you wish to be discussed in these three threads (1-3). Like usually there should be some objective as to the angle you'd like to follow in a discussion, otherwise it's more of a blog type post that belongs to a blog instead of a Forum discussion item that belongs to a Forum.

Could you please edit the intro of your opening posts 1-3 so as to engage other members of the Forum and guiding them to what you would like the discussion to be about.

Alternatively replace the above posts with entirely different content so you can make up the 10 posts total, and I'll then delete my comments.

OR. If you are unable to still edit the above 3 threads, then submit three other posts to make up the 10 posts total and I will delete the three blog post threads.