Ask Mr Robot can be a great tool but default stat weights are not really optimized for your own character.
The best thing to do is to use SimulationCraft to calculate your own stat weights.
1- Dowload SimulationCraft here:
SimulationCraft
2- Extract it in a folder.
3- Launch SimulationCraft64.exe (or SimulationCraft32.exe if on a 32bits OS)
4- Go in the Option tab, then Globals. Iterations: 25.000. Go in the Scaling tab, tick "Enable Scaling".
5- Go in the Import Tab, then Battle.Net. Go on your character sheet. Then click on the "Import!" button, bottom right.
6- Go on the Simulate Tab. You will se here your imported character sheet. Then just press on "Simulate!" button, bottom right.
7- Be patient. When simulation will be finished, you will have in the Results tab your own character simulation result with your own stat weights.
Keep in mind that every time you change a piece of gear, your stat weights will change.
About your low performance in raid, it's quite difficult to help you without any logs.
Try to use your Tigereye Brew with your Fists of Fury. Try to align your Serenity with your trinket proc / use. Use & abuse of SEF when possible.