Is it true that in the US you could drive this monster with a regular driving licence? In the EU you would need either a C class licence(if it's over 3.5 tonnes) or a D class licence(if it can seat more than 9 people). Both are rather difficult to get if someone is not used to driving large vehicles, and require completing additional 20-30 hours of learning, not to mention the fact that you can't get them until you held a regular(B class) licence for at least 3 years(in most EU countries, exceptions apply).
In the US, you can drive a vehicle with up to 15 passengers on a regular license.
The bus has been converted and should be registered as a non-commercial recreational vehicle, so it would be the same license for that... probably a Class A, depending on gross vehicle weight rating.
It's a slight step up in training from your normal vehicle, and would probably require a health certificate, etc... but not as expensive as a CDL (commercial driver license), which would usually entail a few weeks of training and ~$2,500 in costs.
We're picking up the newer series of 5 tons, which get about 7 MPG with the latest revision turbo diesel. Earlier ones get about 4.
Little hard to swallow the fuel cost if you're planning on back-and-forth trips, but my route is a long, drawn out squiggle across north and south America, so we'll only be doing a few hundred miles a month. And, hey, no rent to pay!
Trucks, and everything else your tax dollars go to that the US government doesn't want, all sell at auction on http://govliquidation.com for pennies on the dollar.
My American shoot-from-the-hip response to this would be to consider the road differences. Most American roads, interstate, state highways, and main city throughfares, are able to accommodate large vehicles quite easily. This is not the case in EU cities built for smaller traffic volumes. Many American vehicles are built to spec for these roads, and the difference between driving dad's F-250 and a garbage truck becomes less significant. Tractor trailers, farm vehicles, and heavy machinery are classed differently. But a petrol-driven bus or heavy-load truck is not.
There are a few places in Europe that you wouldn't be able to get to - the centres of some small villages, for example, or some smaller residential streets - but they're a definite minority. Don't forget we have buses and delivery trucks here, too!
Oh yes, certainly -- It's not a matter of the roads being incapable of supporting large vehicles period, but simply that many of those roads are not as accommodating to large vehicles as those of American cities. Thus it would require much more operator care to successfully navigate with those large vehicles.
I required a CDL Commercial Driver's License to legally operate a school bus, nearly identical to OP. I additionally had to have "Passenger Endorsement" to transport passengers (not sure limits on number and relation, like I'm fairly sure I could transport my sister w/o PE). PE also lets me operate limo/cab. There are HazMat and a couple other endorsements. A higher class of CDL is required to operate tractor-trailers, aka semi's.
My employer provided training and I had to pass written and operating/driving tests in addition to medical exam/requirements. This was in Washington state. Similar in the several other states I have lived.