How to avoid contagious media stories affecting Bitcoins? There is an integral connection between fiat currencies and shop prices. 

Can crypto's achieve the same shop use?

If a crypto has a giant user base, It can be less physical than Fiat. It needs to have some physical coin, institutional and material equivalence, how can that be achieved?
Can crypto's achieve the same shop use?

For Bitcoin, the trend is in the opposite direction.

Bitcoin’s soaring transaction fees, following the digital currency’s 1,300 per cent surge in value in the past year, have made it practically useless as a token of exchange in Hong Kong.
“A customer wanted to pay for a HK$56 cup of coffee, but since the transaction fee was HK$97, we had to decline,” said Paul Li, manager of the Crescent Moon in Kowloon, one of 30 establishments in Hong Kong that accept the digital currency in lieu of cash. “The transaction fee was only about HK$5 to HK$6 in August. Now there is no incentive for people to actually use bitcoin.”

SCMP

If a crypto has a giant user base

I guess Bitcoin still has by far the largest user base of all the cryptocurrencies.