Take a look at the picture I posted of mine, the scraper is a piece of 3x3 angle iron across the top, spring loaded and hinged from the frame. Sharpening a scraper bar is unnecessary, it will sharpen itself over time.
Wetting for asphalt is absolutely necessary, and easy. Put a drip pipe across the top of the roller, 1/16 hole every 4" will provide sufficient water. You don't need to drown the roll, just keep a nice sheen on it.
Sprayine diesel works, but diesel costs more than water, and isn't necessary.
Why driveway contractors want 2-3 days of setup time,
driveways don't have the base roads do, they aren't rolled to the compaction roads are, and, it's a lot easier to convince a homeowner to stay off his driveway for a few days than it is keeping the public off a road for a few hours.