Sorry to say that, because this could be a great hack.

Using your hack (both files installed, the old one manager deleted), I had big troubles.
No more ability, for all my employees, to:
1. Establish uniform.
2. Modify charge.
3. Pause his job.
4. Send home employee.
5. Fire employee.

Little Note:  I was able to hire non-family sims (in the shop as customers) only if best friends with owner. Otherwise they refuse always to be hired.

Then I removed your hacks, and all works fine as before (of course without the option to hire family member or friends).

Iceman