First question.
It sounds, from your post, your interested in mainly NEW commercial construction.
Is that all you want to do?
The rest of your questions would depend on what size job you are planning to do, and the time frame in which you have to do it.
For 4 guys, on a big job, yes you would sub out the fire alarm, concrete cutting, and so on, or hire alot more guys.
Fixtures, some supply them, others spec out certain ones and you have to supply them.
First thing first, ask yourself what kind of commercial work, and how big of a job are you looking to land, and how much capital do you have to work with. Large commercial jobs require alot of tools, and quite a bit of digging.
Sub that out to start too.
What do they expect from you?
The impossible, what else........
Dnk........
