K-9 is being used as the base for Thunderbird for Android but it isn't there yet. FairEmail is a lot closer in functionality at the moment.
I use Thunderbird for Gmail (among other accounts) and it has to regularly compress my Gmail box, which none of the Android clients do - in my experience, Aqua Mail, K-9 and FairEmail all struggle with a decent sized Gmail mailbox after a while.
Probably a Surface (if there's one with a 5G modem) at the moment. I got a Lenovo Ideapad Duo Chromebook a few years ago but it's become unusable now and hasn't been jailbroken to my knowledge. There was a newer version but it wasn't made available in the UK. Devices like the Juno look promising but are way too expensive for me (accepting they're around the same price as an iPad and that Android devices are subsidised).
iDrive E2 is $40 a year for 1TB S3 compatible storage and they have promotions quite often. As always with cheap storage don't rely on it and have a local NAS but it's handy for offsite. I've just transferred out of Wasabi, who were cheap but are less so now.
The one headphone adapter I have doesn't seem to work, and I don't think there was one with the phone. Finicky is probably right!
This 2022 Nokia has an FM radio. I had a look at the app and it says 'Please plug in your headset to tune'. It's not impossible that the USB C port is wired so wired headphones plugged in through an adaptor act as an aerial I suppose.
There's a few in Bradford, but then again we're pretty much guaranteed a display at around 11pm every night.
Years ago I lived in a small town on the edge of a new town in the UK and there was a shop that was rarely open but was piled high with used car radios.