Your system is allowed to pick them up and throw them.
Yes.
No. Fresh batteries will be provided and distributed at random. Because battery quality control is not perfect, batteries vary from one batch to the next and even within a batch. Your design must be robust enough to deal with this.
Yes.
Yes, provided no part of the system is in contact with the balls at the start.
Yes.
Yes. However, the "things" must be easily and completely removed within a reasonable amount of time (within a minute) after the run. Also, if significant damage (e.g., from screws or large tacks or nails) or significant residue (e.g., from glue or gummy adhesive) is evident after removal, the run will be disqualified.
Yes, provided the balls are below the top surface of the box.
No. The transport time used in the scoring refers only to the time interval between the post-assembly start signal and the instant when the balls come to rest.
Yes, provided the platform is placed back in its original location. The platform is open on the bottom.
The contest will be held in typical indoor conditions.
After transport, the balls should not differ significantly in appearance or in function (bounciness). For example, the golf ball should not have any significant scratches, and the ping-pong balls should not have any dents or cracks.