Getting feedback from Stakeholders is a crucial activity in Scrum. Working with stakeholders frequently ensures the team to focus on the right things to build. Although it is required to have Stakeholders at Sprint Review, they can also engage with the Scrum Team during Product Backlog Refinement, Sprint Planning or during the Sprint if the Scrum Team requires it.

The Scrum Team members have courage to do the right thing and work on challenging problems. The Scrum Team agree to be open (to speak and listen) about all the work and the challenges with performing the work.
Scrum Team members respect each other's skills, experience, and opinions.

Velocity only measures the team's average speed and does not reflect how much value is being delivered to the customers. Even when it's considered inside the project, while it's important, it's not the key measure of success. The Product Owner should be focused on how much value is delivered to the customers.

The Scrum Master is responsible for removing impediments within the current context of the situation AND boundaries defined by the Scrum framework.