Recommendations for 3.5 switching audio jack which does NOT short to Ground at plug-in or plug-out?
Yes that is normal, the sleeve connection of the jack most likely touches the tip and ring when plugging and unplugging.

Yes, wiring large battery currents via a short-prone audio connector rated for 1A max current does seem like a bad idea. It is a completely wrong tool for the job. There are far more suitable connectors available that are designed for connecting DC power (instead of audio), such as the common barrel plugs.