I owned a 2.2 as my first car that wasn't coming from my parents...
Ran it for well over 150,000 miles without ever seeing an oil leak of any kind (or any kind of leak for that matter).
Never heard of the 2.2 leaking oil.
Might be wrong but just thought I should weigh in...
That said, it looks like you want a focus and so I wish you the best of luck, try finding one an older person owned so you don't get one with a burnt out engine and suspension (lots of kids think the focus is a sports car and drive it as such).