So I've been reading about apoe variants and how this may have a strong effect on what we should eat.

Stuff I've gleaned that may or may not be right
1) People have two copies of the genes, so you can be 2/2, 3/3, 3/4, 2/3, 2/4, etc.
2) 75% of the population have no 4 allele, and 2% have the 4/4 variant. Most people are 3/3. (This is specific to Europeans)
3) 4 is the most ancestral gene, 2 is the newest gene. There are claims that the 4/4 is much rarer now because our switch to a grain-based diet killed off most of the 4/4s. However, I have also read that the 4/4 genotype is actually even more ancient than paleo, and the diet would be more similar to other primates.
4) People are afraid of having 4/4 because that means a significantly higher risk of Alzheimer's, and the associated implications with insurance coverage and so forth
5) Having the 4 variant is associated with higher LDL, and I think especially the bad dense kind
6) However, this is because 4 variants have a harder time getting enough saturated fats in the brain, which is why the body needs to increase the LDL, however, this also increases plaque formation

From those points, are the following questions/comments
1) I have heard people comment that if you have the 4/4 variation you should lower your saturated fat intake because it'll be bad for your LDL numbers, but that doesn't make sense to me for the following reasons:
a) Given the general paleo/primal framework, it would seem to me that having the ancestral allele would make it even more important to be eating a non-grain diet, which means more protein and fat in general
b) If your brain is already not getting enough saturated fat, wouldn't reducing saturated fats just make it worse?
2) However, what does the additional plaque formation mean in regards to heart disease?
3) Apoe4 isn't the be-all-end-all, as there are those who were 4/4 or 4/3 (I forget which) who said their health/numbers improved going on a high fat diet and things sucked on a low-fat diet, but at the same time, there are those who found their numbers better going on a low-fat (esp. sat fat) diet.
4) As such, what should be the recommended diets for people of the various variations of the alleles (or if there should be any variations)? Not enough information is also a probable answer.