I've purchased almost exactly the same setup (Polk TL1's instead of OWM3s) along with some white ball mounts and after reading so much about Atmos speaker placement that my head was spinning, I think you're basically right within the reccomended ballpark in a 5.1.2 setup:
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This is from Dolby's reccomended placement chart, basically 80 degress (10 degrees in front of straight above) is optimal, but it can range as much as 65 degrees (25 in front of you) to 100 degrees (10 degrees behind the listening position) and still be within spec.
As with floor-level speakers, toeing in (and down in the case of height speakers) is absolutely the right thing to do, as on-axis frequency response of speakers (especially smaller and cheaper ones is always better when they're pointing right at your ear 'oles. I always laugh when I see photos of supposed "audiophile" setups where all the speakers are at right angles to the walls because you just know the people are more in love with aesthetics than sound, or heaven forbid, music.