Mathematically speaking, the optimum is to keep Proficiency and Brutality the same. Always split them 50/50 (except in difficult raids where a boss has a hard first phase or difficult end phase where you would skew them accordingly). In PvP, if your average Determination level is above 50 (you can see on AoU dps meter) then you should stack Determination as it will increase your damage much more than Proficiency and brutality. In that case you should split them in a ratio of 1:2:1. So a quarter of your stats in Prof, a quarter in Brut and half in Det
For defensive stats bloodlust is awesome as a bard because you deal a lot of damage, you're going to be constantly healing yourself, but make sure not to neglect vitality so you aren't a 1 shot target
Anger is only useful for PvP, completely useless in PvE, but even then it's still pretty awful as it takes forever to put wound complexity on people. You should keep around 10 Tenacity. If you get wound complexity, add a little more, if not, then it's high enough
Mathematical formulas (in case you want to see) sourced from
this post on the Russian forum.