If open-uri supports the same actions then it's cool. 

I'm just asking you to not write code that you don't understand what it does: ask about it, find out what it does and if that's what you want. "Programming by coincidence" is an anti pattern.
So no don't delete them, just make sure they work and you kind of know what they do.

And I found the passage, thanks!

"If you need to send certain headers or actions to the web server, you can use the :method, :headers and :body styles to customize the HTTP request. (And, if you need to go beyond these, you can always break out Ruby's OpenURI class.)"