Pax Vobiscum,
Your 1.
I agree the threat is relatively slight, or we'd already have airliners dropping out of the sky like hailstones.
But, I think you will agree, that from both "anecdotal" evidence, and some of the info in the links quoted earlier, one has to assume a correlation between the use of PEDs (personal electronic devices) and anomalous behaviour of aircraft systems (mostly radio nav type systems, that would be the most susceptible).
And secondly, that establishing that the use of a PED was a contributing factor in a crash is well-nigh impossible.....
Your 2.
Picocells would keep down the 'baseband' power, but wouldn't reduce the spurious emissions I mentioned.
And yes, when such a picocell fails, I'd prefer to be in another aircraft, too.