Absolutely agree with NgKahCh$ng. :p
You got it wrong, like most Singaporeans would.
"I'm friend to everyone" is correct; the sentence implies you're an ally, not an enemy. You don't say "Are you a friend or a foe?" but "Are you friend or foe?" The latter is more idiomatic, even if the former is technically correct. Likewise, "I am a friend to everyone" is unidiomatic and of inferior literary construction.
If you intend to say you're a friend (not merely an ally), then it would be better to say "I'm everyone's friend" or "I'm friends with everyone" or "I'm a friend of everyone's".