Hay @chris2jh ,

thanks for your question :) Lets see if I can answer everything:

Is the SteemJ API a library to create new Steem-based blockchains or it provides interaction with the same blockchain that Utopian and Steemit are using?

So a Steem node offers an API by default (It is using JSON RPC) - SteemJ is a wrapper for this api written in Java and allows you to interact (Post, Vote, Transfer, .. ) with the Steem blockchain.

Utopian is an initiative that rewards open source contributors. So basically it is a way for me to earn some more rewards for the work I've done.

I'm just curious to get on the developer mode some day.

I am more than interested in collecting feedback - Most of the best improvements are best on the ideas and questions of users. So if you want to start something with SteemJ feel free to ping me on discord or on steemit.chat and I will try my best to help you :)