Mallorca is very different to mainland Spain.
We have all read scare stories about the Spanish Government suddenly forcing a demolition order on some honest, unsuspecting person who has purchased or built in good faith.
It is not possible to comment properly as all cases are different.
The key thing though is that local regions (who have granted permissions) may have periodic inspections from Government in Madrid and have to comply with their ruling even retrospectively.
However, in Mallorca all property matters are handled directly by the Mallorcan Government in Palma who have autonomy over the island and are not handled by Madrid. Therefore any decisions could not be overturned without something extraordinary happening. Also in Mallorca new building is very controlled (to maintain the quality of the Island) and the major part of the real estate market is resale.
Essentially, using a bona fide Solicitor, (as we would arrange for you) will ensure you are properly looked after.
Mallorca, although Spanish, is very much independent.