1) Its entirely possible dividing by 10 would've worked (I haven't poked at the math really to see). There may be a reason for the values though (obviously some skill values don't divide evenly, but a bit of rounding might not be too problematic.).
2) There were 2 problems with 3rd Edition that the generic-ness of ATOW's life paths addresses (IMO). The first is what in other games would be called "codex creep" where as time went on some 3rd Edition Life Paths where just BETTER than what came before (In fairness, this creep problem is also solved by the ATOW modules having point costs)
A second issue is timing. 3rd Edition was released over such a period of time that the Life Paths were spread out over just as many years. Early Field Manuals have RPG rules for 2nd Edition, while after 3rd was released, the Field Manuals had rules for 3rd Edition, and those factions with early Field Manuals languished with 2nd Edition rules for a long time. The same would've happened with ATOW if they had tried to make specialized Life Paths for each faction. It took something like 10 years for all the Handbooks to come out. Imagine telling Kuritan players that they won't get their Kurita-specific lifepaths until the Kuritan Handbook came out...
Sure, you can shove faction specific life Paths into the main book to avoid this timing problem, but now you're looking at having dozens of extra Life Paths, and that makes the book so much bigger. Imagine having to have the space for a House Specific Academy (maybe 2 if you want to have a "Good" Academy and a "Bad" Academy. Oh, and their own ToD as well. And maybe their own Organized Crime Modules. And then add in the Periphery factions. And the Clans. 3rd Edition got to the point where there was a book almost entirely dedicated to Life Paths alone.
The ATOW system with the Affiliations allows for people to make characters with some factional flavoring, without having to go overboard and coming up with dozens of extra Life Paths and figuring out where to publish them and how to do it in a schedule that doesn't make some factions wait years for their paths.
And yeah, it can lead to feeling like some of the characters are cookie cutters, but Affiliations, Flex points and Optimization at the end should be enough points to make them actual characters.
3) These aren't so much useless traits (since the traits are useful), they're just not given enough points to full develop them. I treat them as possible hooks for the character that you can explore if you want to, or not. The best part about it with the Optimization system is that the hook is basically free.
Its more like a pre-order than a Christmas present. "Oh hey, you want this trait, you can spend 5 points on it now to start the process. And if in the end you decide you don't want it, you don't have to buy it AND we'll refund the points."
If ATOW didn't allow for the Optimization of points, then yeah, I think the awarding of non-fully actualized traits and skills would be an annoying thing, but you don't lose anything if you decide you don't want it.