If you didn't need to worry about the technical junk behind the scenes that makes it work.. what would be the features of the perfect cryptocurrency?
Unfortunately the technical part is not junk.
Imho a perfect cryptocurrency will be completely anonymous. If one wants to show the transactions and the content of the wallet (audit) special view key should be available to be provided.
The perfect cryptocurrency will have (almost) instant blocks and confirmations. Of course, the network fee will be less than one cent per transaction even in the most busy days.
The perfect cryptocurrency will have extremely easy to use wallet, tutorials and so on.
Obviously it'll be decentralized, it'll be accepted everywhere for buying goods and services, it'll have a strong security against whatever attacks (51%, replay...).
And this coin's value will never decrease (or at least not much). And it is fine to stay at the same value, it doesn't have to rise either.
And I'll end also with "unfortunately".
Unfortunately because of the world as it is, and also because of technical difficulties, many of these "wishes" cannot come to live.