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Batteries have come a long way thanks to the huge market for high power rechargeable equipment like power tools, vacuum cleaners and Teslas. There are far more plants producing them now and manufacturing process are improving constantly.
No they are not PCB protected, your protection is using a good quality high current (amps) rating battery and a decent device. Unless you had a dead short circuit in a mechanical mod you should never get into a position that overstresses these batteries. I doubt you can get protection circuits that would work at vaping wattages unless you vape quite low, but they add a few mm to the battery and wouldn't fit any of today's devices.
IMR is a battery chemistry that would guard against chargers not stopping charge properly amongst other things, but I don't think they are made any more as a small change in chemistry negates that and good chargers are cheap and readily available today.
AW (Andrew Wong) was a supplier/manufacture who reportedly bought only the highest grade batteries and relabelled them, that was great 8+ years ago but not needed now the cells recommended above are even better.
For 25 A 18650 I would recommend the Molicel P26A or Sony VTC5A in that order, there may be others I am a bit out of date.
As Postmodern Smoking go by the continuous rating as there is no standard pulse time, manufacture may mean current for 0.1 second, another 0.5, another 1.0, you would have to find the datasheets to know.
No expert, I have not used them much, but close the air flow before filling and if the top-cap is screw-down type them turn upside down as soon as you can when screwing it down, it creates a little pressure as reduces the air volume.