i would like to have some tool that can monitor bluetooth traffic over the air and report/show what is going on. for example it would show when devices do pairing, when they connect or disconnect (and what the other device is), when they send data (and what the other device is).

would this be possible to do in Linux?

Try this:
https://wiki.wireshark.org/CaptureSetup/Bluetooth

Im not an expert but Bluetooth is encrypted so seeing the data stream over the air is not possible. You might be able to see pairing depending on what version is being used to communicate.

that makes sense. and i'm glad it is encrypted, despite its short range, a possible excuse for not encrypting it. it might also have been not encrypted due to the expected small scale electronics in small devices like ear-buds. perhaps there is an option, when pairing, to not encrypt so that very tiny devices, with extremely tiny digital electronics, can be supported.

my first goal is to see how much pairing activity there is, and supplemental pairing of new devices that power on or come into range. i can understand encrypting even a target address (including connect), so i would not get to see more than pairing.

you are basically saying "Try Wireshark".

@Skaperen Yes, I misspoke.
Another thing you might consider is a Windows micro-utility called BlueToothView by Nirsoft. From what I read, it will do most of what you want. But of course, it's not Linux, and you can't use it in a script. But perhaps it's so small, that it would work under Wine? Sorry, I would have mentioned this earlier, but my mind hasn't been in Windows mode much lately and I never used those utilities very much. The *nix-like OS' are better. Hope this helps.

i mostly skipped Windows. i did use Windows 98 at work. i spent 4 days to get clean install that did not crash daily like it did for everyone. then i got a complaint from a network admin that my desktop was holding some shared volumes open so long that backups would fail to run. he asked me when was the last time it crashed and i replied "2 or 3 weeks ago" and he told me everyone else had a crash daily, even if they were not at work to use it.

i did have a copy of Windows 98 at home. the box was still in shrink wrap. i never used it. it was just on display that way. guess what my 5 PCs were running.

nice. even an email for suggestions. thanks.

My pleasure, welcome.