Lovely shots, sort of thing I do (mostly seascapes in my case) and, frankly, not very challenging for a our cameras (it's why I use MFT for landscapes, I need a reasonably high quality camera and good lenses that I can physically get there without ruining my fun, an uber camera that can focus on a fly in flight and take pictures of hummingbirds by the light of a single match is no actual help).
I'm not sure why you were having trouble with the night shots in the first post, the OM-D range has really good low light facilities if long shutter speeds aren't a problem, perhaps this should be a "what did I do wrong" rather than "what should I buy" thread
For general purpose photography then without doubt a fast FF dSLR is still better than MFT if you don't mind humping it about. You have trouble beating a Nikon FX camera with the 24-70 f2.8 as a general purpose camera, and had I known life was going to have me photographing rescue dogs instead of strolling about doing landscapes I'd have kept that combo rather than selling it and buying MFT.
Perhaps, again, rather than "outgrowing", you need two systems.
I don't think Oly have the resources or inclination to produce a camera with fantastic C-AF and MFT loses you two stops unless you use f1.2/1.4 primes (some here, more coming) or f1.4 zooms (not going to happen, and would be as big and heavy as FF f2.8 zooms) rather than the FF f2.8 zooms.
I had this dilemma myself some years ago, when using FT. In the end I went Nikon FX, which let me do stuff I hadn't done before but simply spoiled my fun. Now the game has changed a bit because FT has morphed into MFT, the sensors are (relatively) better, and there are faster primes.
Just thinking on my feet here, I'd consider an second hand FX camera and the 24-70 f2.8 and see how you feel after a month.