I also have the OM-1 and Nauticam combination (woohoo!) and will be retiring a beloved E-M1ii housing and bodies. I was glad Nauticam was prompt with the housing release, as we're heading to Bonaire in mid-June. I was on the cusp of changing systems, but am really glad I waited--The OM-1 shows great potential.
I've had trouble over the years with the Olympus mini-flashes (the one which comes with the OM-1 is the same FL-LM3 which came with the M1ii), and so I trigger strobes with an iTurtle, which works great (and unlike the Nauticam trigger, supports TTL). I'm pleased with the camera so far, and think the focus improvements will be really helpful (I do note that the 60 focuses _much_ more reliably on the M1ii than the smaller bodies). I have two batteries (although haven't gotten the "free" one yet), but the battery life seems materially improved, so I'm thinking I may reliably get three dives out of a charge. As to the 30, I have the Olympus version but use it only for blackwater/bonfire dives, as the working distance is small. I mostly use the 12-40, the 60, and the Panasonic 8mm fisheye.