If you want to learn something specific, you can ask me any time.
How would this work to exchange coins on 2 different chains? (e.g. Eurocoin + BTC or LTC + BTC?)
If everything's on one chain, it seems to check out (colored coins etc.) and only Bitcoins current limitations regarding fees and block size would cause issues (SERIOUS issues!) there.
Yes, it is a part of the colored coin client, sorry for confusion.
Bitcoin limitations affect it no more than they affect normal trade. If you're concerned about
potential ban on small-value outputs, you can represent 1 USD with 0.0005 BTC, for example. I doubt that they will ban such outputs.
If coins are on completely different chains however there might be a way to at least lock funds of market participants.
Yes, there are problems with cross-chain trade, but I think it can work reliably if miners do not collude. Worst thing which can happen is your funds being locked for a couple of hours.