...I am generally concerned about dilution of the name by copycats...
And from the list of them you gave, I can imagine "Fastcodes" in particular being popular for a potential competitor.
Even if assuming services accepting viᖚes won't rebrand themselves as "Viᖚes_____", the significant downside fact (and hurdle or barrier to entry) that vibes are not now associated with the action of gaining access to some good or service is the negative trade-off to the positive aspect that we would hope viᖚes would become a social phenomenon and thus people would associate the synergy of spending and receiving viᖚes as an a nearly silent action of their normal internet activity to be a form of "global village synergy" a.k.a. "jamming together with the netizens". The upside of that trade-off is there can't be any portmanteau copycats of vibes. And the huge upside being that if it is branded as a social phenomenon, then it is very unique and concise and precise on the social synergy (i.e. it creates a new concept of money and powerful new meme)
A tricky one, and not a decision I imagine you are going to toss a coin over! Abstract or descriptive (with attendant merits and demerits)?
I think there is a superior term than netcode, which more precisely expressing an unlock key to be used in cyberspace. And the currency symbol is very precise!
The "keys" of Netkeys I think could have more meaning than "codes" for a wider audience. And I do like
⚷ chiron (U+26B7)

A distinctive and timeless symbol / logo. Almost Pictish! EDIT: Just realised it's an astrological symbol.
