E-M5 | Absolute Best Settings for Big Landscapes

Anti shock is a good idea. If you don't want to use a remote cable, the 2 or 12 second delay shooting mode works fine with a shutter press, unless it is a long lens.
Noise reduction does the dark frame subtraction to remove hot pixels, and might be a good idea if you turn it on for dusk or nighttime landscapes. I think this applies to Raws and jpegs as well.
The noise filter setting doesn't matter as you are shooting raw.
Only ORF is possible, DNG is not in an Oly camera.
Keep IBIS off unless you notice the camera is shaking on the tripod, then consider it an option. If you are shooting wide angle landscapes it isn't really an issue.

You might want to read up on proper orientation methods for your polerizer to achieve maximum effect (or jsut rotate it until you get the effect you want in the viewfinder).
I would manual focus at 14x to ensure you get the correct area in focus. Also perhaps the DOF preview button might help you select the correct apeture for the desired image.

The most important thing would be getting the right lens for the shot, in my humble opinion.