@snerkler
re: EM1.2 shutter, I find it no more or less sensitive than my former Nikon D3300, very easy to rest your finger on the button to focus etc. and not take an accidental shot. In continuous mode it's not so easy to take just one picture, but then my Nikon shot at 5fps and I shoot the EM1.2 at 10fps.
re: Panasonic 100-400mm, I bought one recently and at the moment I'm hugely underwhelmed by the image quality, I find stopping it down an absolute must, but then it's been very dull and grey lately and the opportunity to use it in bright sunlight hasn't presented itself. The first race of the season for me is Sunday week, 17th Feb, I intend to take the 100-400 and see what it can do and hope there's some sunshine around that day.