It's not actually that difficult to build a fully feautured tip bot. The hard part will come with bullet proofing it and integrating with the STEEM blockchain.

Correct! That I know of software engineering, features are usually easy, in my line of business we call this marketing stuff. The real stuff, stability, resilience, scalability, integrations with other system are the difficult parts. When done that right, with top level performance vs hardware resources, you enter the game of high value IT software for which millions of $ are requested from customers.