I can see how the different audio and video issues would be frustrating. I'll definitely try my best to help you with this. As I don't know yet which Slingbox model you are using, I would advise you use components. The component cables are the red, blue and green. You will also need the red and white audio cables.
Since you did mention you tried different ways to connect, you would need to confirm you are configured to the correct source. Since you are using component, that is the source that should be selected. You can check through the Slingplayer app on your mobile device, and going into settings. If it is not selected, I will provide a link below on how to fix this.
If you need further assistance, I would need to know what Slingbox model you are using and how you have it connected.
Sling Media Moderation Team