It depends on your state/county requirements. Check on the local website for your area.
In Massachusetts it is necessary to obtain permit for roofing a house.
This depends on the location of the property. In most cases, no permit is needed because you are replacing existing. If there are any structural changes, there will be permits required. Check with the state that you live you, as well as your local township/bro office
Yes you will need to have a permit pull & inspected to be covered by your homeowner insurance.
As others have said, check with your building inspector before starting anything to major. Where I live the answer is no.
If Florida, yes you do, by a licensed roofing contractor.
As many others have stated, the first thing to do is check with your local City/County and find out their requirements for replacing a shingle roof. Most Cities/Counties do require a permit be pulled and for the roof to be inspected to make sure it meets all local code requirements.
Typically not unless removing or adding wood.
In California you should always get a permit for a roofing project. Also, be sure that your roof is Title 24 compliant.