I'm going to do a carrier swap to get this going. Are there still issues surrounding porting and activating iMessage/Facetime anymore or have they sorted that mess?
There should be no issues with this at all as long as your number stays the same.
Should be no issues. Often there are though where the overseas sms aggregators don't update your carrier quick enough after a port, so your iMessage/FaceTime activation texts go to your old carrier and disappear. Eventually their tables update and they go to the right place. Sometimes within minutes, sometimes days.
I have ported about 100 connections and never had an issue.