The "skipping" approach works, requiring less delta-V than a true ballistic trajectory, and goes back to the Saenger antipodal bomber of WWII. With a gravity profile similar to that of the "Vomit Comet," I wouldn't enjoy the ride. Packages, maybe.

The idea is not to get too complicated. Space launchers work best when you get out of the atmosphere as soon as possible, and stay out of it as much as you can. No drag, no heating, and rocket engines operate at their highest expansion ratios.

Hypersonic spaceplanes that ride at high Mach numbers through the atmosphere may save propellant, but propellant costs are about the tiniest proportion of a launch cost, and the challenges of high-speed long-term atmospheric flight resemble the challenges of making a submarine that can go 400 miles per hour.