Football fans wouldn't have voted PO anyway - so it's no loss. Incidentally, the fans we're talking about are not the "mainstream" fans - these are the ultras, and their political views are always going to be on the right of the political spectrum, no matter what country. Bear in mind that many "ordinary" fans are supportive of PO's measures - because it makes the stadiums far more friendly places.
As for people being frustrated - that's not the word on the street. There are plenty of newly-middle class people who will always vote PO because it offers them the best hope - the only frustrated people are the ones who have been whining and complaining since 1989 about everyone. It's the same old in Poland - but the last few election results show that the electorate is satisfied with PO.
I think SLD will take some of the frustrated PO voters but Palikot, as much as I dislike this man, is playing his part in taking some of the voters too. Apparently his movement/party now has close to a 5% backing [if what the media say is true, although recently he was supposed to have had only 1%].
Indeed, it's possible. But bear in mind that Palikot isn't an idiot - if he can play kingmaker, he'll get PO to support some of his policies and will back them in a coalition as a result. Likewise with the SLD - they will support PO if needed because they can work with PO - they can't work with PiS.
Bear in mind that the Polish electoral system has never resulted in an outright majority. Even if by some utter shock, PiS managed to win - PO would still manage to put together the magic 50%+1 - because PiS has utterly alienated the PSL, SLD, et al through their actions. The *only* way PiS can win this election would be to be in a position where a coalition with the SLD is enough to pass 50%+1 - and then to get rid of all the "hawks". That's not going to happen. Oh, and bear in mind that it would also be electoral suicide for them - their voters would never again vote for a party that shared power with ex-communists.
The SLD are also pretty damn unlikely to agree to any coalition unless they were in charge of security and justice - they know what PiS did to Samobroona and LPR - do you really think that they're going to let PiS use instruments of power against them as well?
In a strange sense, Kaczynski has led them to electoral success and yet oblivion. They're firmly the 2nd party in Poland, yet they're totally unelectable - a huge contradiction, don't you think?
I've looked, looked and looked again at the electoral mathematics - and I just cannot see how PiS can win this. Even if they get over 40% of the vote (which would be a massive shock) - the PO/PSL/SLD/Palikot/etc parties would simply find a way to keep them out.