Computing technology is much further today than it was twenty years ago, but kids these days understand less about them because the technology is abstracted away better. (People use iPads now with no idea how a file system works.) In the 32nd century stuff feels magical, a lot of people probably don't need to know how it works to use it.
Floating nacelles make plenty of sense if they're independent drive units with all necessary components in the nacelle, consider they create a warp bubble around the entire assembly, but you can obviously wirelessly control a separate structure and the ships can manipulate them with force fields and such. Think about how many times a ship in earlier shows scraped a nacelle and exploded, separation is good design if technology now allows it. And remember... this is like many hundreds of years after Starfleet had timeships that could beam a person to and from any place in space and time. If anything the technology in this series feels a bit not magical enough for the time period.
