I've done some reading but I'm still trying to figure out what this coin is about. Are they trying to become a marketplace for trading coins/assets across various protocols?
If so, what protocols can be traded so far? Only Colored Coins?
LKK is not that much a coin, it represents shares. 100 LKK = 1 company share.
And yes, the focus will most likely be always on colored coins. But they also connect other blockchains. Solarcoin is already available:
Lykke Integrates SolarCoin into Global Marketplace
https://solarcoin.org/en/lykke-integrates-solarcoin-into-global-marketplace/...and Ethereum will follow soon:
Lykke is Integrating Ethereum
https://lykke.com/city/blog/2016-09-30/lykke_integrates_ethereumI'm not sure about further plans, but I believe it's safe to say that there will be other blockchains as well.
Is the marketplace decentralized? If not, how is this different from Poloniex or any other centralized exchange/marketplace?
In the link above (Ethereum-integration) there is an explanation:
"Lykke is a semi-centralized exchange. This means that the exchange does not take possession of the traded coins (Ethereum tokens, Ethers, Bitcoins or colored coins), but needs to be trusted to match trades correctly. Lykke has a centralized matching engine and decentralized coins settlement. Matched trades are settled on the blockchain in the atomic way. Each atomic transaction must be signed by both parites and the exchange. Still to be able to trade, one should deposit his coins to Lykke exchange. Depositing coins is not equal to trusting coins. How can it be? Lykke uses multisignatures mechanism to hold client's funds. Lykke exchange can not spend any coins without a client's private key. Even if the exchange is compromised and the Lykke key is stolen, the client will not lose his coins. The second key is required to spend deposited coins. Lykke exchange also provides a refund mechanism to guarantee funds recovery in case of emergency. (...) "Here is a graphic about the tech:
https://lykke.com/technology.php
Why is the total supply of LKK over 1,200,000,000 if only 30,000,000 are available? Where are the rest?
Total supply is: 1,285,690,000 LKK
https://www.coinprism.info/asset/AXkedGbAH1XGDpAypVzA5eyjegX4FaCnvM/ownersThe company/founders hold it. I believe one could say that it technically would be available but it's not on the market.