The project's libraries are missing. Project doesn't compile. Additionally, it is impossible to know which library versions are intended to be used and whether these contain known bugs or vulnerabilities.
Both Distributor.sol and ProxyFactory.sol expect to use the OpenZeppelin contracts library.
Low. Project doesn't compile. Impossible to know what version of the libraries are intended to be used.
None.
Add libraries as git submodules or use a dependency manager such as npm. In both cases, always link to a specific revision or tag to know which version of the libraries are used.