Other than separating people, and different leaderboards, they are basically the same. Usually a ranked match is actually ranked, while player matches are just for fun, but that doesn't seem to be the case here. You can rank up in player matches also. So I don't see the point of having them both. Is this a bug, or is there something I'm missing here?

You can't play with a party of friends in Ranked Matches.  But honestly, I can't play with any of my friends period, so really, there isn't any.  :/

I think its really just for the ranked leaderboards, nothing else

You can't take friends into a ranked match.

I believe the difference is that if you finish in first place in a ranked match, you are supposed to stand up and give yourself a round of applause. Otherwise, I cannot see any distinction other than the one mentioned above (regarding friends and such).

I can actually be in a team with my friend in Alliance in ranked.