Been here over seven years.
People tell me my accent is "Funny" (not American, not Scottish). But it all depends on who I'm talking to and in what context.
I have actually forgotten American words to things... I struggled one day to figure out what an aubergine was called, for example. And my sister used the word 'faucet' in a sentence the other day and I realised I hadn't used that word in years.
I write in British English - I was totally crucified on my American English when I wrote something when I first moved here (not fully realising words like centre were spelled differently). So to fit into the expected business and social norms, British English became my normal mode. And again, I don't even realise I'm doing that anymore either.
For me, dates should always be written "DD MMM YYYY", regardless of where in the world a person is. This way, there is never confusion. (This is from years and years and years of working in medical regulated industries where you have to do this).