Then your imagination is sorely lacking. I can guarantee that their popularity will severely decline within the next 5 years, because right now they are attracting a lot of "protest voters" who have little interest in their actual programme and simply vote for them because they attack the established parties in some way. This kind of thing always cools off after a while (just look at Die Linke).
Whether the Pirate Party can survive at depends on how they deal with that when (not if) it happens. I'm pretty sure they will, since their core points of informational freedom and transparency are still getting more relvant.
They had an absolutely ridiculous amount of (free) media coverage during the Pirate Bay trial, the FRA-law (that gave the government the ability to snoop on internet traffic crossing the border) and ACTA (a law written by the media industry to help and prioritize illegal file sharing) but, they have never breached the 4% barrier required to get in parliament in Sweden.
While the outrage during the FRA-law was quite impressive (more impressive on the internet than on the streets unfortunately) both ACTA and the FRA-law passed, and today I don't know if I've heard anything about the Pirate party in Sweden for the last year (I hear much more from the Pirate party in Germany - a few years ago I believe the exact opposite was true (that the Pirate party in Sweden was by far the most successful in Europe)).
I hope I'm wrong but I don't see how the Pirate party will ever get into parliament in Sweden and the only thing I can hope for is that the German, and other, Pirate parties will be successful and that that result in changes within the EU as well as reignite the spark in Sweden.
But I barely even dare to hope on anything.
On the long run I see them around 8 to 10 percent, depending on region (more in cities) and which positions they take in areas like education, finances, taxes... At least if they can stabilize their internal structure and avoid the problems I mentioned. But this will be enough to make them interesting as a partner in coalitions, especially together with the Green Party and that way forcing the established parties to rethink their own positions.
This will omnly happen when governments and businesses stop trying to take away our freedom, i.e. not soon.
> That's a similar situation as the Green party had to face many years ago, when they had managed to establish laws to protect the environment.
Well, the Green Party still exists, and is doing rather well in Germany.
2) Yes, because they managed to move from a single focus to become a party with an established program and well known politicians. But they have very similar voters and so that new party is partially splitting forces. The Green Party will maybe react by adjusting their program in Pirate direction.
But of course a lot of things can happen and we will see. At least this Pirate success will show certain interest groups to be careful about their actions. A party that can jump above 10% out of nothing just about a single item of interest was something not expected by them. They will have to recon with that force.