I will deal with your misunderstandings in order:-
The Social tax issue has a ten year phase in time so the Italian demand for these taxes to be paid in Italy is not going to happen overnight as long as the people are paying the social taxes in the EU state in which they reside. The link below from the UK tax authorities might help you with this.
HM Revenue & Customs: National Insurance: New EU rules for flight and cabin crew working in two or more Member States
If you read the EU directive you will see that if your Home Base is changes frequently you can apply to have the social taxes paid in you state of residence and NOT at the home base state, I would think that a lot of people in Ryanair would fall into this category.
I am very sorry to say that as of a few weeks ago the French were still not giving my friend any access to the social security system dispite having paid all the taxes due as a resident of France for the last 25 years,unless something has changed in the last month or so this is not as you say bull!!!!....... It is fact.
On the matter of EU states getting their act together on income tax I refer you to the post above about the Dutch workers in the Danish salaughter house.
The answer to the question is very much in the second paragraph above, in theory the EU state should pay out Pensions and the like if you have paid the taxes but with the current state of the southern europan economy's what do you think the chances of getting your full entitlement are when you are living and trying to claim your money from the other end of Europe......... Or to put it another way if you lived in Sweden and were based in Athens were would you want to pay the money that will keep you in your retirement ?
These governments know that the cost of taking them to court and the time it would take to get the money due from them is prohibitive, in other words you will run out of money for the leagal action or die before the case gets to the European court.