On top of that we are all hopefully always learning. New kinds of security attacks will come along and we will have to figure out how to address them.

I would encourage you to consider trying hard to build a team around your project. In my experience open source software is hard work and really only can thrive in a community. This doesn't form magically around the software. It takes time and effort to build. If you can get good security folks in your community you can learn a lot from them.