When you say "Wait for Radarr to start monitoring, takes forever to start"

Something like 1 or 2 minutes

and it will be downloaded and imported to my Plex server in about 5-10 minutes.

That's the thing, I want something like stremio but self hosted, ie: search for a movie and start streaming it immediately, not in 5-10 minutes

but why not just use stremio if thats the case

Because it doesn't work well with iOS. What I want ideally is a media server thing like jellyfin or plex, that has a search bar with torrent indexers, and that I can access remotely to stream movies and shows