If you're living in England, then yes, of course you're English. Duh. I have, however, in my younger, even dumber years, made the mistake of calling a Scotsman an Englishman.
He started screaming something unintelligible about making me into a haggis.
But to call everybody who lives on those islands west of France 'United Kingomers' doesn't really work, so "Brits" ye be. It's easier (and safer) than trying to guess their origin (particularly to those of us who can't always discern between, say, a think North Yorkshire accent and a Scottish accent -- maybe you folks can tell, but I sure can't).
As for the "Limey" debate -- I did ask my friend Sabine (lives in Greenwich) whether "Limey" was actually derogatory, and he said "no, I don't think so."
I'm aware that somewhere along the line "Yankee" went from insulting to not, and I suspect this is the same. (Honestly, I'm still trying ot figure out where the term 'Yankee' came from, other than the stupid song.)
Anyway, so calling someone a Jaffa is calling them a limp-dick, eh? Haha. Good to know.
So are Jaffas similar to McVies?
--Jaeger