Aussie here. They have the right to go through all your devices if they suspect you of smuggling or working or wanting to work illegally in Australia. They will read through all your private messages and have them translated if not in English. Even then I’ve never heard of airport security giving a rat’s ass about pirated stuff.
Hmmm I’ve never used Fen so I’m not sure if it works without premium services, but it sounds like RD isn’t working. Did you check if the files that are showing are from RD? It’s highly unlikely that the latest John Wick only comes in 4K. I recommend trying Stremio + Torrentio + Real Debrid, the UI is just so much better and addons a lot easier to install than Kodi. Also I’m using my old laptop instead of Android boxes. It’s a lot faster plus it circumvents the issue of sharing Netflix with someone not from the same household.