If you don’t understand the study itself or in general if you’re interested in it, it’s always a good idea to also read a good news report on it; see this and also this. They found carrot intake rather than beta-carotene, the focus of prior studies, has this association and figure 6 was just to show that they don’t have much data on daily intake of a carrot or more.

Higher accuracy was achieved in an earlier study where another team used large fMRI machines (it was featured in the version for May). There participants listened to audiobooks / speech while being in the large machine; I guess long training would be easier here but it’s more limited since it’s EEG. However, they claim they have exceeded 60% by now.

The study is here.

In 30 prospective studies with 9331 cases reporting plasma α-carotene levels, summary [relative risk] was 0.80.

10% reduction of less frequent intake of carrots seems more robustly backed by the data. Hopefully, some new study provides more info how big of an effect daily carrots have; see Figure 6.

No, they just added lots of data for one of the multiple things that current emulation efforts (just like neural networks / brain-inspired AI software) so far didn’t even include (neuropeptides).

There’s no reason for why it would now be possible to simulate complex nervous system processes, but maybe this could enable getting closer to that. I don’t know what you mean with “outside behavior” though. Maybe you’re referring to the behavior in some simulation like this?