I am the only Licensed Tech working for my company, how many techs can be employed, and do work for that company, and am I responsible for all of them?

The answer is cumbersome but here goes, No limit to the number unless they are on a site that requires a personal license and then you must be there with them and you may supervise only three. Yes. You are responsible for all work performed by the registered unlicensed technicians whether you are with them on the job site or not.