Re: Uplink module.
I think this concept was in the Bluetooth standard from early on (Personal Area Network + Dial-Up Profile IIRC), but it's never been implemented worth a damn, let alone to the extent that you (and I) dream of. Shame, because if it hadn't been so fragmented and inconsistent it was a strong enough brand that it could have gotten us there. But the interests sponsoring and implementing it were just too abstruse.
Current wifi kit in today's smartphones has probably got us closer to the sweet spot TBH, since most smartphones can share their data connection via tethering, as long as the mfr. or carrier hasn't nobbled the capability. I'd have killed for a phone that did that ten years ago.
What would be really spesh would be if the phone could tether wifi-to-wifi, so I didn't need to duplicate the wifi credentials across all the secondary devices (nor indeed put possibly redundant extra load on the AP, nor increase the attack surface on what might be an untrusted network beyond a single device). I know the hardware can do it (it's pretty ubiquitous on white-label Atheros kit anyway) but it's not a feature I've seen in phone software. If anyone has, I'm interested.
I would say, though, that it's arguably a bit of a "niche" use-case at the present time. Currently most people have, at most, one specialised net-ready device besides their phone/data-enabled-tablet that they'd actually carry around with them. For me it's my laptop, because I'm far too verbose/sausage-fingered to type all this drivel on my phone ;) For others, it might be a DSLR camera that's better than you can find in a phone (though I suspect that example's days are numbered). When you're at home, none of this matters as much - although if a single device could really smartly wrangle being my router for all the possible connections I might use both at home and everywhere else, in a sane manner or at least following policies I defined, I'd be into that.
Be a bit of a bugger if I lost it down the pub though.