concerning where the heat comes out, lift the hood and check to see if the small, hard plastic, black vacuum line by the firewall, on the passenger side, is apart. It should be over where the hoses go to the heater core, but right up against the firewall. It is possible that that line has come loose. Reconnect and this will give air to vents instead of just floor and defrost.
Concerning the no heat, all I can think of is that if your heater core is good, you need to check and see if that when you set the heater from cold to hot, that it is actually doing something. It will be hard to see/find, but see if you can somehow see if when you change the setting from cold to hot, there should be a wire (almost coathanger wire thick) that draws a door closed. That is what sets it to heat. If that wire is somehow disconnected, then it is not pulling the "door" or "flap" shut. That is definately one reason that could be the problem. That wire is also held to the flap with a plastic
piece and if that piece has broken, then the wire isn't connected to the flap and if it has been previously set to cold, then you won't be able to draw it back and, therefore, no heat. That is what is actually wrong with my car. So I just leave it on hot setting. I know I may be being kinda vague, but that's really all I can think of now (This is if the core is fine). Hope it helps a little.