Newbie Olympus Lenses

If by outdoor and landscape, do you mean you hike? How important is portability to you?

Your choices will also depend on what in particular you like to shoot. For my self, I find the 12-40 is wide enough for most landscape and hiking/backcountry skiing uses and long enough in landscape in many cases depending on the topography. I carry the 12-40 on most hikes (if photogenic), and also carry the 35-100 F2.8 Panny (instead of the 40-150) about 40% of the time. The FL is long enough at 100mm for mammals in nature - unless you want head shots like you can get at the zoo. The far less expensive 35-100 would be a reasonable option as it is supposed to be very good. While the 12-100 is likely to be as good as the 12-40 (except for astro/landscape) the question would be, "Would you always want to carry a lens with that FL on the upper end. My own experience tells me no. You might be different.

I also shoot ultra wide perhaps 10% of the time. For me, because when I shoot UWA, I am likely to go as wide as I can, the 8mm F1.8FE is my choice. It is light, is very wide - 180 degrees - and is great for astro/landscape. By centering the horizon, you will not be able to tell the lens is a FE in landscape - excepting if you shoot around trees. Even then, the FE gives the opportunity for imaginative compositions with a bit of an arty look.

My current camera is the original EM-1 which works well enough for all I shoot (I have 2 of them). The new EM-1 II would excel comparatively for birds/sports. The EM-5II is another good choice.

The only time I need the ultra wide aperture of the FE or the F2.8 of the 12-40 is in astro/landscape. Otherwise, in nature, I never need an aperture wider than F4.5-F5.6. Shooting people hiking at dusk would be different.