Resulting damage generally is. The repair itself usually isn't, since faulty workmanship is excluded.
Tools and equipment covers them in the vehicle and on site. General liability doesn't.
Not for yourself as an owner, but you need it the moment you hire helpers, including casual labor.
A business owners policy often fits, but confirm it covers the trades you actually perform. Scope matters more than job size.
Only if disclosed. Undisclosed work such as electrical or roofing can fall outside coverage.
