Hi Petr, and welcome to the forum
2. change in OR - that could come about from 2 sources, Malta and EU
Malta - change in govt to labour looks very likely, in about 18 months time - the labour party has said very little about its likely policies on anything, and not on OR. If Malta got into Greece type trouble, then tax on worldwide income for foreigners would be an easy way of raising revenue, at least in the short term, although in the longer term it may actually reduce its tax take as foreigners leave Malta, or don't move here - if worldwide taxation was introduced I would leave
EU - possibly yes, but other countries have similar schemes - eg UK and Ireland
In reality, I believe the HNWI scheme will be a flop, and Malta will see practically nobody taking it up, and it will have to be substantially adjusted.