The integrated taxes would be a very big step for the EEA, so would common company law and governance for these entities.
That said I think the headline proposal (single entity type and single registrar) is not important. The UK and (AFAIK) the US have few practical difficulties with multiple registrars and variations between jurisdictions.
I agree it is Eu-wide or pan-EU rather than pan European.
Its probably not going to solve the problems it sets out to given all the differences between EU countries legal systems, tax, regulation etc.