There's a couple of possibilities. One is that there is some interaction between your renderer threads that is causing lag. Another is that adding an additional layer has caused the system to perform additional GLES composition, and that's slowing you down. (See this doc for background.)
The "objects are never display" statement makes me a bit unsure as to what the actual issue is.
Either way, one approach to correct this is to eliminate the camera SurfaceView. You can send the camera preview to a SurfaceTexture (API 11+) and then render the contents on the main GLSurfaceView as a textured quad. An example of this can be found in the "Texture from Camera" activity in Grafika.