In the UK, these expressions are very current and popular. I used "eat humble pie" the other day and often say "it's not my cup of tea". I hope you use them a lot!

Never heard "Dont egg on her" in my life. I'm from England. The other expressions are pretty common in British English.

I agree with Michael. All of these expressions are very common.

In my opinion, most of these expressions are old-fashioned. Probably "Don't egg her on!", "This movie is not my cup of tea", and "It's a piece of cake!" would be most popular.

It really depends on where you are from. The English users who have commented on this even differ in opinion. So here is the Irish opinion: "piece of cake!", "egg her on!" and "not my cup of tea" are heard on a very regular basis in Ireland. I would argue you would hear them all in the space of a week or so. The others however, are understood but not used. They are considered old fashioned and you may get a funny look if you use them. (They can sound out of date or "cheesy" just like "gee whiz" or "oh golly gosh!")