I like the ideas, for the 2nd one could we have say a minium of 100 posts before you are allowed to advertise something to cut down on scammers and time wasters. not sure if this is feasible.
They are good ideas but I don't think they would be used too much. If somebody has something to sell they can happily put it up for sale in the CCFC section as long as it isn't a scam or spam, the same for travel. I don't think they would be that busy and may sit empty