The hard right is getting closer to power all over Europe

I think it is a bit of a stretch to claim they can't be kept out. It is certainly reasonable to observe that they haven't.

It would be perfectly possible to reduce the numbers to tiny / inconsequential.

It was worse than than that they would only let him speak on immigration not on economics, he was rail-roaded into sticking only to immigration. 
Another example of how proper debate gets stifled, it is not that BNP would have succeeded yet it might have given better ammunition to others. 

Oh well why didn't you say that then, it is but it isn't, feck me Sid, are we even from the same planet?

Short of some extreme deterrent such as a shoot to kill policy. I don't see how we can stop them. 

I await your suggestions

It's semantics. It is quite possible to stop the phenomena we see now without resorting to machine gunning down boarders. However, even that drastic a solution might become justified politically at some point if the current situation is just allowed to just roll on. After-all, people would have been told what the consequences could be and they are not compelled to break into a country. "Don't climb through my windows or you may be shot" isn't that unreasonable at base and most people understand the logic.

The solution is to remove the incentive. The draw at the moment of the prospect of being able to force yourself into another community. It's pretty obvious how you would withdraw this incentive and make attempting to grasp this opportunity un-inviting - barracks, wireless free accommodation on a barren, windswept and remote promontory. The irregular applications would fall to a trickle and some of the genuine cases might end up getting exactly the help they need (security).

This might be in reference to EU's appeal to help Italy with its migrants. It's possible Germany is not keen.

IMHO until the priority shifts from finding various ways to get them in to keeping them out, getting unity on the matter is going to be tricky.

There is a classic paper that I usually refer back to whenever this question arises. It poses and attempts to answer the question "Why is it that (only) western liberal democracies are plagued by unwanted immigration?"

The author notes that “… some states, such as the immigrant-receiving states of the oil-producing Middle East, are very efficient at keeping out, or sending back, unwanted immigrants.” The Asian tiger economies are equally efficient in that regard.

He further adds that "Western liberal states have implemented self-imposed limits on their own sovereignty, including their ability to properly control immigration... The capacity of states to control immigration has not diminished but increased—as every person landing at Schiphol or Sydney airports without a valid entry visa would painfully notice. But for domestic reasons, liberal states are kept from putting this capability to effective use.”