I'm probably a bit out of my depth here, but maybe somebody else can jump in and set me straight. Regarding point (1), I think that may be mostly solved by cons

I'm probably a bit out of my depth here, but maybe somebody else can jump in and set me straight. Regarding point (1), I think that may be mostly solved by conservation of energy if the vehicle is large compared to its payload. The reason is that, as it climbs, it will have to be accelerated to orbital velocity (I'm assuming this will be done by the cable itself, or more accurately the mass at the end that keeps it in tension). It will then drop its payload, and climb back down. During the climb down, the cable will have to decelerate the climber back to surface velocity, so the energy that went into speeding it up on the climb will be mostly recovered on the way back down. So it seems like the cable would sway backward as it lifts the climber, and be pushed forward almost as far when the climber descends again. If the mass at the end of the cable included some kind of constant low-grade thrust, maybe you could bank up angular momentum between runs to account for the mass of the payloads. I'd love it if someone with more physics background could weigh in on it though.