EM1 Mk II and 100-400 - help needed!

After years of using Panasonic M4/3 cameras (most recently GH4) , I've been tempted to change and bought the Olympus EM1 Mark 2, which arrived last Friday. I particularly want to use this camera with my 100-400 and had a couple of opportunities to try it out this week - with mixed results, so far. I'm convinced my failures so far are either due to a combination of incorrect settings and operator error, so any help pointing me in the right direction would be gratefully received.

An initial outing with the combination on Tuesday resulted in some decent shots of deer, ducks, etc:

- I didn't have a great deal of luck with some gulls in flight but that was partly due to them being too far up and too fast for my (lack of) panning skills.

Today I headed for a nearby hide to try to catch some smaller birds at relatively close quarters and though I got a few nice sharp shots - the majority are not. I'm not sure what I've done wrong or whether I've changed something inadvertently whist experimenting. I've used this lens many times with my GH4 at similar speed/aperture settings with good results.

I used CAF with low speed sequential (mechanical) shutter set, and tend to work in Manual with speeds 1/500 - 1/640 for subjects like this and using auto-ISO. The image stabiliser option is set to S-IS AUTO and lens OIS was turned on. I'd heard of the problems with the focus limiter, so had this set at Full and today I tried setting the in-camera version at 0-10 metres. I'm not entirely sure whether it was after I set this option that most of the problems occurred, as some of my earlier shots seemed OK. I'd also changed at some point from using single point to 5 point focusing. Is there anything I can use that will show me all the settings used for individual shots, so I can see if there's a pattern between the good and poor shots? I'm not entirely sure if it's a mis-focusing or stabilisation issue - either way it's left me feeling somewhat frustrated and disappointed.

Thanks in advance for any help!