People do say 'flower' as a term of endearment in some regions of the UK. A variation on this is 'petal'. This is used especially  in NE England, I believe.

And a very common term of endearment in Scotland is 'hen' !

By far the commonest equivalent term used between men is 'mate'.  I remember getting on a bus once. One by one the passengers, mainly women, got on and paid the driver. As each person got their ticket, the driver said 'Thanks, love', 'Thanks, love'. Then, when he realised that he'd said this to a man by mistake, he corrected himself by saying 'Oh, sorry, mate!'

As I glance over my article there seems to be one or two mistakes that I don't remember making???

Anyway, just to correct :-)

-It’s actually a very nice, casual word of “endearment” to female passersby

-In Ireland...not In the Ireland 

Hiya! It's an interesting article. I notice that many expressions and term of endearment are regional. I bet your experience of UK would have been different if you had picked another area. I live in the South West of UK now (I'm a french speaking Canadian) and I heard people calling me "love" but never "flower".  Here, we tend to say I'm "knackered" or "bushed" instead of "wrecked".

Like you, I love the expression "it's raining cats and dogs" (which I read about in a grammar book) but I've never actually heard it said. Not once in 8 years. I heard "pissing down/rain" though! Nevermind.

That is really interesting ;D.Thanks a lot ;)

'Gone/Going to see a man about a dog' is one of my Euphemism topics, like the anachronistic 'Gone to powder her nose', or 'Where can I wash my hands'.  My father used it occasionally and it took me years to work it out.  So too it took me years to work out my mother's quip: 'See you layder' - 'Nod if I see you first'. 
I should ride it up - when I get a round tuit.