I am happy that its useful atleast to certain extend.

If i needed to become a contributing developer on Steem, what would i need to know?

The blockchain is written in C++ and uses Boost.org C++ libraries. For compilation it uses Cmake and make. Further the use of various data structures and construct from Boost libraries is quite extensive. Apart from the new RocksDB integration and the adapter, there is also an in-memory database called ChainBase which is essentially the blockchain state in memory. Apart from the blockchain code where it maintains the consensus, other parts like witness, rc etc are written as plugins. P2P (Peer to Peer) component ensures the data being sent and received from other nodes in the network. The APIs are essentially exposed by the above mentioned plugins. The final piece of the puzzle seems to the cli_wallet tool which is one way to interact with the blockchain.

In general either hands on experience with C / C++ and experience in UNIX network programming I assume is needed to start contributing to the Steem code base. (Computer science educational background or self learned will be quite helpful and make one efficient)