Please help me understand hard drives, transferring files wirelessly, and playing to media players.

I have several questions that, when taken together, are one big question.

1. Are wireless hard drives a thing? Can I buy a hard drive that I plug into a power outlet and then upload and manage its contents over wi-fi or Bluetooth? Are there big problems or limitations with this?
2. Are there limitations when playing from a hard drive to a media player like file size or format? Are there players that can just play everything with a simple interface, or am I always going to need to mess with third-party apps like plex or Kodi and find half of my library unplayable?
3. What is the simplest way to go from a hard drive/USB thumb drive to something that can interpret the files on that drive to a HDMI out?

I have a giant collection of ripped DVDS/BLURAYS and old, obscure movies on a massive drive. I want to be able to move handfuls of files to a hard drive or thumb drive and play from that device in a way that outputs to HDMI. Is that a big challenge? It seems to be, but maybe it's my lack of tech-savvy. I asked on a home theatre thread but everyone pounced on me because it's not a home theatre question, so I'm hoping it qualifies as a tech question! Fingers crossed...