Hm, I still think we don't have the full picture.
For example online tangible product sales is not covered, as it's not a service. (If I understand the explanatory notes correctly.) But selling software is covered, because you can electronically deliver it. Bah.
Yes, the crossword or sudoku provider has to fiddle with VAT, just as an app store. But if the crosswords are made by humans, then it's not an electronic service. The necessity of the human element seems to be the deciding factor.
Furthermore, the point is that this is a step in the right direction, a unified legal requirement, because before this providers were simply ignoring the VAT, and Member States' tax authorities were not really enforcing it.
Regarding the inclusiveness. This is a problem of legal harmonization, eventually one law/statue/directive will come out on top.
So, I'd just go with the IP based approach, the important thing is good faith. Not a 100% correct solution. And you can always display a warning next to the price that you are not sure of the taxes to apply, so please dear end-user select where you are established.
And yes, national (member state) tax offices act rather dumb and macho when it comes to collecting money.