Removing ALL post process effects and even the rendering of the objects (But not shadow mapping), I get around 900+ fps. Enabling the rendering of the objects and simply outputting it on the screen (using a full screen quad), without any lighting or anything, just the diffuse color, the fps drops to ~46-51. Then obvoiously after adding all the post process effects afterwards, it goes down to 20-30 fps. (The scene as described above, terrain [displaced and tesselated], plane[pom], cube).
900 FPS sound about right, but for the scene with objects. An empty scene should be ridiculously high FPS. So does dropping from~50 to ~30. But the huge drop from 900 to ~50 is a problem. Try to make sure that only the most simple rendering is used. Maybe you can replace the shader with one that only does world-view-proj and for the pixel shader outputs a plain color, like red. This way you will see only filled outlines and for just a few objects you should have huge FPS. Make sure that the CPU is not involved in the rendering of objects. And check your render targets. Maybe they are floating point. Do a test with a simple A8R8G8B8 to see if they is any noticeable change.
Also make sure if you are using SMAA that you stencil buffer is cleared properly and the rendering pipeline is set up appropriately. I found that on simple mistake with SMAA on high settings can half my normal SMAA performance and at the same time look a lot worse.
Sorry, I can't give you profiler tips because I do my progiling in code, not with an external tool.