Hi.
Yes, you can prevent to see queues for users or groups, and you can also prevent creating tickets for users or groups in certain queues. See this screenshot about group permissions on a queue:
About SLA: Yes, there are tutorials, and setting up SLA is not very hard: Managing Service Level Agreements (SLAs) in RT — Best Practical Solutions
But: We never managed to enable escalations based on SLA, and although I asked in several places but no one could help us: RT 4.4: Configuring escalations with various rt-crontool options, but none are working - #4 by Daniel_Rauer
Bye, Daniel