Rear tire carrier answers...
Here are my answers to your questions:
Does the tire carrier latch open or does it just swing freely?
The latch takes a bit of force to open and close...not enough to be a problem of course but enough to make it truly secure. There is no play in it when closed...which means no rattle. When opened, there is a small rod (not hydraulic but something of that nature) to allow the tire to swing out in a controlled manner. Thus, when you open it, it does not just flap out and slam against anything. I have heard though that you should take care to not let it just swing open freely because the weight of the tire (especially larger ones like mine) can allow it to swing to much and break the rod. I am obviously careful of this but it in no way is a problem that I can see.
Does the tire carrier come off easily?
I have not attempted to take the carrier off and thus I don't know. My guess is that it does not. I think if you take it off you would also have one or multiple unattractive holes in your bumper.
Any extra wind noise from the tire?
No apparent wind noise that I can hear. Of course, the roof rack and the 265/65/18's make enough noise that I probably wouldn't notice anyway. But no, no noticeable wind noise.
Hope this helps.
-Josh