For full-time living, there is a difference between homesteading and a nomadic lifestyle. We have both types here, in addition to recreational users.
For full-time living issues, try the "Escapees" forum at http://www.rvnetwork.com/index.php?&&CODE=00
Most of the members at Escapees are retired or close to it, but there are some younger nomads, also.
For construction/conversion tips and other information, look here at skoolie.net. For a basic background on vehicle systems, read "Poop sheets by Phred": http://www.phrannie.org/phredex.html
1. Check the "Working on the Road" threads at Escapees for job opportunities and ideas. Also do web searches on "workcamping" for more resources. There are places you can park free in exchange for part-time maintenance, office help, tour guide, etc.
If you are going to pay for your parking and work as a tradesman, then pick something you like and are good at. Doing something you hate every day because the money is good is no way to live, in my opinion.
2. Free/cheap parking depends on whether you are passing through (Wal-marts, Cracker Barrels, truckstops, casinos, fraternal organizations) or are parking for an extended period while while supporting yourself. There are guides and web reports suggesting where to stop when passing through an area. Cheap extended parking, such as siting on a friend's property, requires developing personal contacts. There is no set formula for this.
3. There are (gravity) dump stations in numerous places, such as parks, campgrounds, and some truckstops and rest areas. If you go the non-typical route of using a macerator pump, you can dump with a garden hose wherever it is sanitary to do so. I don't have a bus yet, but the port-a-potty from our camper dumps right into any toilet. The macerator users say they can run the garden hose into the toilet, too. Some others prefer not to have black tanks, but to compost their waste or use a bucket method. Read on.
4-5. As far as costs, It depends. Each bus and each living situation is different. There is a whole range of options from elegant to dirt cheap. Read on.
6. If your bus is registered as an RV, Federal law prohibits states from requiring a CDL to drive it. Your state may require a special non-CDL license endorsement if the RV is over a certain weight or length or has air brakes. If the bus still has seats in it, registering it as an RV or using other options for operation without a CDL may not be a available before the conversion. Once you are legal to drive it in your state of license, reciprocal privileges will usually if not always qualify you to drive in all other states.
You will generally get a CDL in the same place you get your state driver's license. Check with your local DMV-RMV-DOR or whatever, or look for their website. You may have to wait until you are 21 for a CDL. You can't get one in New York until then, and that age limit may be part of the Federal CDL law.
But here, a driver's license at age 18 is good for 26,000 lbs GVWR or GCWR if the vehicle transports less than 15 passengers. Gross Vehicle Weight Rating is how much the bus is designed to carry, including vehicle, fuel, driver, and passengers. I see a lot of buses for sale at 25,500 GVWR.
Gross Combination Weight Rating is the design load of the bus plus the design load of the trailer. You can pull up to a 10,000 lb. trailer with a regular license if you reduce the tow vehicle GVWR by the trailer rating, for example down to 16,000 lbs at the 10,000 lbs. max trailer weight rating.