I think you guys are underrating a few of these

• 8 could be useful if you’re a spy and want to have your own private documents that noone can read
• 1 you could leave oysters in places suited for eavesdropping, and maybe even coordinate billions of them to tackle down ships etc (?)
• 5 It would be possible to all of the sudden communicate with all humanity in morse code by turning them on and off, you would hit headlines and maybe demand a crazy amount of money in cardano/bitcoin or else you’ll just blow up the toast industry. Plus, this morse code thing could lead to a cult where you might have fanatics at your advantage

3 and 7, teleporting a short distance like that can be extremely useful to get past roors and fences. Identifying whether a container was empty or not reliably is good enough proof to clean out this list without being powerful enough that the majority of people would actually believe I have magic, plus I don’t have to reveal my teleporting ability.