Once you've sorted out your cassette I've found 10 speed Sram doesn't like too much tension in the cable to the rear derailleur. With Shimano I would pull it through as much as possible and really clamp it down but Sram likes to have a tiny bit of give. So when you set the cable tension leave the inline tensioner slightly screwed out so you can give it a little slack ones you've tightened the cable retention bolt.
Once you've sorted out your cassette I've found 10 speed Sram doesn't like too much tension in the cable to the rear derailleur. With Shimano I would pull it through as much as possible and really clamp it down but Sram likes to have a tiny bit of give. So when you set the cable tension leave the inline tensioner slightly screwed out so you can give it a little slack ones you've tightened the cable retention bolt.