Placing the codebase on GitHub would allow folks to work and make contributions in the form of a Pull Request, which the OP can reject with explanation if it does not go in the direction they desire. They can even setup a roadmap and tickets (issues) to help guide eager-to-help offers.
For anyone wanting to take the project in a direction OP doesn't want - they can fork it and do just that.
So no, don't beware of offers to "help" - be aware of your time commitments and that not everyone's goals will always align with yours. That's just how open source works...