I have the whiterun and riften homes on dif toons. In both homes I find the red wall plaques and the wooden weapon racks. None give me the interact option like mannequins. Is this just broken? I am on 360 so lack those nice concole commands

Its a problem on all platforms, not just the 360.

Make sure the weapon you want to put on the rack is actually equipped on your character. Then select the rack. If you are not getting the descriptive pop up, look at a different place on the rack.

Oh, if there is something already in the rack in the game, those are not the racks you put something into, your racks are empty when you start out the game.

So far I managed to get everything working by buying the house and all upgrades -before- entering the house for the first time.
Though this method doesn't seem to be completely failsafe for everyone, it worked for me so far.

My weapon racks work flawlessly.

So does mine, except for the Staff of Corruption which falls to the floor. I'm pretty sure that's a bug with the staff though.

I know my house in RIften shoots the weapons into the walls when I try to place them.