It does seem that the holder is designed so it encompasses a section of the bulb after the E27 thread stops so even if the line and neutral are reversed hard to touch the screw thread, however the standard safety feature of the MK shockguard lamp holder where the two pins need pressing in before they become live can hardly be done with a screw thread lamp holder. So one has to question the "Safety tested and tamper-proof to protect little fingers." once bulb is removed can't really comply with IP rating, however in real terms not a problem with ceiling mounting.
White is the USA colour for neutral and blue is the European colour for neutral since the instructions are in black and white it would seem designed for USA where black is line and white neutral, so even with two colours the instructions really tell you nothing. One would need to test to find what colour the centre pin or line is.
To be class II it must have a class II sticker,
it does not matter if it is safe, without that sticker it needs an earth connection, light in the room I am in at the moment is class II but the ceiling rose is not, that includes the hook on the ceiling rose. If the centre bolt is plastic then it could be class II but if that centre bolt is metal the connector block in the fitting would need to be in an outer shell so impossible for a stray strand of wire to touch that centre bolt. This is how I got my last shock in my father-in-laws house, one strand of wire made the metal of the lamp live.
I had to find a class II lamp for my mothers kitchen, it was a real pain, loads of lamps clearly would be unlikely to give one a shock as 99.9% plastic, but they did not have the
sticker, I had to pay a premium to get a lamp with the sticker, the 2D lamp I ended up with looked exactly the same as the lights at half the price in B&Q, but they didn't have sticker on them. The electrician employed by the council to wire my mothers kitchen insisted the sticker must be on the lamp, and I think he was right to insist, I seem to remember a batten lampholder or a pendant set has to comply with BS EN 60598 I see nothing on advert or instructions to say it complies. If it complies with BS EN 60238 then the neutral does not need to be connected to the Edison screw.
I have seen so much sub-standard electrical gear marketed by Ikea I simply don't trust the brand of electrical good, a chest of draws fine, but electrical stuff I would not touch, to have an instruction set in black and white where wire colours is so important to my mind is wrong. And also not to provide in the UK a terminal block with a loop connection is also wrong, I know you can fit the junction box already shown in the ceiling space, but the lamp should be designed to hold the wires inside the fitting safely.
If the through bolt is metal then the connector shown without some casing around it is not fit for class II connections, class II is often referred to as double insulated and without a shell around that connection I can't see how it will comply if the through rod is metal, however if that rod is non conducting then it would comply.
