Do you think it is a good idea ...

[The Mikado]

The Economist is worlds superior to the other two, but its style guide is so formal and set in an early-twentieth century form of English that I wouldn't recommend emulating their writing style.  They and The New Yorker are the only publications I'm aware of that still use æ, œ, and diaeresis marks in English.  As long as you understand that no ordinary person would spell "cooperate" "coöperate," go for it.

[The Mikado]

Tender, with regards to the diaresis marks, I was referring to the (now archaic) English practice that if you have the same vowel twice in a row in a word as part of two different syllables, you put the dots over them.  No one has seriously done that since the late-19th or early-20th century outside of certain publications like The Economist, publications that desire to be the preëminent authority on the English language .