TLDR you are not playing effectively at the high end and that is the difference. Functionally you are playing well enough for the most part, but the gap between a 91 and 99 parse is far greater than the gap between say an 80 and 90 parse:
1 - you are wasting rage, this leads to less outburst procs and thus less damage. You are sitting at 100 for large periods during non-execute phase. On some bosses this may mean you need to eat a mechanic to maintain uptime.
2 - You are not spending your outburst on shield slam in ST. You spent it on 7 shield slams (right), 8 thunder blasts (not right but not dismal) and 7 thunderclaps (bad). Probably your biggest damage loss.
3 - You're playing roar and not spear on a boss that is largely immobile and you can capture the most out of spear. Probably costing you damage.
4 - You are tunneling the boss and doing zero damage to tangles. Even in your current talents executing the tangles would be both beneficial to your dps and to the raid. Playing heavy handed over BSV would probably give you some more though not really necessary.