As to your questions - as every such system, be it blockchain, tangle, etc., it may and will be used for every purpose ordered data storage can be used. Simply because coins on the market are just immutable, time-ordered databases. The same applies to Bitlattice. It will enable use as coin, but also all else that above mentioned can be used. It will handle contracts as well. Plus some interesting extra features.
The prototype will mainly serve as a coin, but also as a proof of concept and reference implementation.
Yes nodes will be incentivized, proportionally to their participation in network.

As to website. It's not the most important thing right now and also requires some care. So, yes, but it can wait.

BR,
H