I think it's illegal to block someone in their drive, but not out of it. If not, it's the other way around.
Parking is so bad around here that we now have people who live in other roads parking in our road and on the grass. In cities and big towns I'm sure that happens all the time, but I remember when you could park outside your own house and everyone did and there's no space as it is. Yep, I'm that guy now.
BTW, if you see people flying flags over here (which used to be never but is certainly a lot more common) they'll almost certainly be the flag of St. George rather than the Union flag. Also, it's more likely to be hanging out of or from a window than a flagpole of any kind. Unless it's on a vehicle.
The only person I can think of who uses a flagpole anywhere near me is probably a Vexillologist becasue s/he flies flags of different nations pretty much every day.
As for things which annoy me (and staying with cars and parking) people who own too many cars and do not have the space for them piss me off, but my real ire is saved for the fact that cars are just too big now. Nothing in this country is or has been designed for cars this size and it's causing more and more problems, accidents and anger. Plus, the really big ones look silly on our roads.