Hi @roboFisherman,
Cool design, thanks for sharing! 
I’m interested in non-standard methods of controlling underwater vehicles, and have added a link to this post as an example in my advanced control proposal/feature request for ArduSub. The sliding mass for pitch control was not something I’d considered before, and is a cool idea (that also makes a lot of sense to factor in as part of a robust dynamic buoyancy control system).
The more interesting open-source projects the better - even beyond your suggestions, it may be useful for people to see working examples of some of the mechanisms, and potentially just use specific parts of it in their own alternative vehicle designs 
If you do end up open-sourcing it, I’d recommend adding your 3D print files to Printables so they can be shared (by us and others) and replicated more easily