EU plans have been leaked showing Poland as a border state outside a revised "mini-Schengen".
It's the Daily Mail, which routinely makes up all sorts of stuff just to create sensation online. They're very, very good at it. That map you posted - did it not escape your attention that Latvia is in blue, which clearly means it's a pile of bollocks?
After all, PO had years in power (with Tusk himself at the helm) to ensure Poland's border security requirements were on par or exceed the standards of the members of this planned "mini-Schengen".
They are. The only thing that Poland could do a bit better would be to impose a frontier zone with Russia and Belarus, similar to Finland and Lithuania. Apart from that, Poland has done a fine job of protecting the Schengen border.
while there is pretty much zero infrastructure along a proposed (allegedly) border between Poland and Germany
Off the top of my head (border crossings being my specialist subject and all that), the infrastructure has mostly vanished from that border. It would be theoretically possible to reactivate the crossing in Kostrzyn nad Odrą as the canopy is still intact, but most of the buildings are now used by the gmina and a private nursery. I'm not sure what they did with the booths, but they were stored nearby not that long ago. Likewise, it wouldn't be too difficult to reintroduce controls at Świecko as some of the infrastructure is still there. Olszyna is also theoretically possible, although a lot of the infrastructure is completely ruined and the car infrastructure has been demolished. I *think* the old crossing at Garz is still intact, too. Apart from that, everything else has been demolished or removed to my knowledge. There are still some buildings intact and not in use (particularly on the German side), but the actual road infrastructure has gone. In places such as Zgorzelec, the motorway crossing was completely demolished, and the Polish border crossing in the town was completely demolished and new offices built in place. I think there's also one pedestrian crossing near Zittau that's still intact.
Not much really, and in many places, the infrastructure has been so comprehensively removed that it would take a lot of money and effort simply to put in anything resembling permanent controls.
and even less infrastructure along the Czech-Polish border (but instead the best part of 800km of very hard to patrol space),
Exactly. Not much remains at all - I've explored many, many places along the PL-CZ/DE borders, and both PL and CZ ruthlessly removed a lot of the infrastructure within a couple of years. There's still some remains near Hradek nad Nisou (the buildings used for pedestrian control are intact), but there's really not much to write about. The border has been opened so comprehensively that it would be so difficult to return to the pre-2004 state of affairs - and even then, many border crossings were open for tourist crossings anyway. The border as early as 1991 ceased to be controlled in a serious way - the internet is full of stories of people just jumping over fences to visit the Czech beer shop or the Polish meat shop with a blind eye being turned.
But definitely along the PL/CZ border, very very nothing remains of the infrastructure needed to even conduct EU border controls. It's not like Hungary that kept almost everything intact (although ruined) - they really did demolish absolutely everything. Even in Cieszyn, mostly everything has been demolished and a Castorama has been built on the site. There's still some facilities for truckers (likewise on the CZ side), but nothing of the scale needed to reactivate controls. Meanwhile, the pedestrian crossings in Cieszyn/Cesky Tesin have all been demolished or turned into shops.
What *is* realistic is Greece finally being told to shut up and accept EU help when it comes to patrolling their waters. The Greeks are whining and moaning about it, but I cannot understand why they haven't been told to either accept or face being booted out of Schengen.