The EU has many good points and advantages to Cypriots but it also has many dis advantages. From memory EU law takes precedence over the laws of that member state and from what i can gather there may be some changes required to the Cyprus constitution to allow this to happen. There is freedom of movement of people and goods throughout member states, there is also the issue of EU funding which is basically the richer nations subsidising the not so rich nations. There will be attempts at harmonising prices throughout the EU although there is a lot of transparancy on this eg a carton of cigarettes in Spain costs about €27, in Holland €35 the UK £51 (equivalent €71). Local taxation plays a big part in these price differences.
There was a big thing a couple of years ago with the working time regulations which said that anyone working over i think it was 37 hours a week had to sign an opt out agreement. Another useful or useless EU directive? useful for some but not for others.
In summary the main advantages are the trade and freedom of movement of people, however there are some poorer countries which accessed the EU and lost a high percentage of their labour to other countries because they could earn more money there.
One of the biggest dis advantages is that for some reason prices seem to go up. Especially when the Euro is introduced, countries like Spain and France when the Euro became their currency the price of a beer went from equivalent £1 sterling to 3 or 4 € which is about £2 to £3 sterling in a very short period of time.
Good or bad? probably best for countries whos economies need investment.