Me and a friend used to wire, program, end user train, and hook up monitoring in 3 homes a day using Ademco Vista 10 (Hardwire) Panels into finished homes every day, so It can be done by two.
As far as pre-wiring homes I know 6 guys that keep up with 25 different residential projects and they are the cleaning residential cabling installers in northern cali. so it all depends on experience and expertise.
Home automation, on the other hand, is something that requires an ample amount of time in order to be done correctly.
What does kill me is newbies thinking they are doing anyone a service by attempting to run cabling in homes with limited knowledge, everyone suffers in some way for your misplaced enthusiasm in residential electronics.
If you don't even know if your state, county, or city requires specific types of licensing for low voltage installation (security) how could you possibly know the state codes for anything that you are installing.
It took me 5 years to get all the necessary licensing where I work because my state requires 6000 hours of verifiable work experience in security, besides other necessary certifications in order to be in the field.
Do yourself and your potential residential owner (victims) a favor, and work for a company that already knows what it is doing before you jump into an industry that demands attention to detail and proper training in order to be productive and efficient.