Scrum does work. Not with all teams in all situations, but it has been shown to work.
I would suggest trying to embrace textbook Scrum as much as your business environment allows, see how that works out, and then tune it.
Why does your Scrum master not want to move tasks out of the sprint backlog? Does he not 100% embrace the principles of Scrum? (I would see that as worrying in a Scrum master)
Most problems implementing Scrum are actually just problems in the team or business being exposed by the Scrum process e.g. - if your sprints are thrown out by unforeseen support issues this suggests you are not allocating enough resource to support
