Seems like you have it all thought out, building better foundational tools like Vessel and block explorer will probably bring the most value from you to the ecosystem at this time and I support that decision fully.
When it comes to ChainBB, as a forum owner, I'd say keep it around if you can. It still serves its purpose well, and if it only requires minimum effort and time I'd say it's worth it to keep around. Maybe down the line you can shift more focus to it, yours or your future employees.
I like it a lot what you have done with Vessel, only thing that my needs find missing is posting. Can't wait to see what you come up with V2.
Thank you for your hard work.