Process uploaded videos so that they are in a streamable form that any device can play. Though costly in resources, this is a critical part of PeerTube, so tread carefully.
Uploaded videos are reviewed before publishing for your account. If you want to add videos without moderation review, an admin must turn off your videos auto-block.
The threats to privacy with YouTube are different from PeerTube's. In YouTube's case, the platform gathers a huge amount of your personal information (not only your IP) to analyze them and track you. Moreover, YouTube is owned by Google/Alphabet, a company that tracks you across many websites (via AdSense or Google Analytics).
You can import any URL <x id="START_LINK"/>supported by youtube-dl<x id="CLOSE_LINK"/> or URL that points to a media file. You should make sure you have diffusion rights over the content it points to, otherwise it could cause legal trouble to yourself and your instance.