Vat in the Azores is now 15% there is nowhere now in the EU with a rate less than this, although soem of the newer member states were given a period of grace for boats that were already registered there when they joined. I think Malta was one such example.
RCD/CE compliance is required if you wish to sell the boat in the EU and it is not exempt. If you have no intention of selling the boat in EU waters then it may be possible to ignore it, although if you are officially importing the boat, then that may be a different matter.