The US does not employ passports or visas within it's borders. Therefore one can travel all over the continental US using buses, automobiles, trains, planes, or motorcycles. The method is up to you.
yes
For US citizens travelling within US, you just need a valid government issued photo ID, you can use your passport for this.
None needed for travel within US
Not unless you are the driver.
Passports are not required for travel inside the US. Anyway, non-citizens, legal or not, are not eligible for US passports.
They can, as long as they don't get caught.
Only in the US and it's territories.
This will depend on where you want to travel. If only within US then you need a valid ID, if international travel you need you passport, visa and other requirements like immunization and such.
No. Passports are not required for US citizens to travel by air within the United States.
None needed to travel within the US.
yes,as long as you have no criminal record.
Yes, but you will need some government issued photo id (Driver's license, etc).