Hey, they are pretty standard ERC-20 tokens, so they technically can be traded on an exchange. However, right now all of the coins have pretty low volume, so most exchanges probably wouldn't list them. A decentralized exchange built on 0x would work though!
It was my impression that any coin could be listed on certain exchanges if you pay the fee to do so. Depending on the exchange it could range from 50k to 1 million USD just to be added.
Yes, that's usually about right for most exchanges. But if your coin isn't popular enough, they usually will not add it.
However, there is a protocol for decentralized exchanged called 0x. Any tokens on Ethereum can be traded on this protocol, using websites like Radar Relay.