The FEIE is only concerned about your relationship with America. It doesn't matter what country/countries you decide to live in.
As far as the transition, I didn't know it was happening until much later. When I left America it was to travel full time. I wasn't specifically going to one place so saying goodbye to friends and family was like, "I'll be around. Catch you guys later." 2-3 years later I was thinking to myself, "Oh shit.. You're like.. really gone."
For work, I hold myself pretty strictly to working on US east coast hours so there is as little friction as possible with the employers. I moved my phone to a virtual provider and updated all banking and W4 paperwork to use a mailbox service in Florida (no state level income tax in FL).
You do get very bored with tourist stuff though. I think I would rather die than set foot in another museum or see some old building or religious site or whatever.. Now 100% of the travel I still do is to see people I care about.