How do Items like "Spines of Seething Hatred" affect the type of a a spell?

Solution 1:

I have no way to verify this personally (so, grain of salt, et cetera), but the Diablo Wiki says this about the Spines of Seething Hatred:

The unique affix turns Chakram into Hatred generator: instead of spending Hatred, it generates one. However, for all purposes, it still counts as secondary, Hatred-spending skill.

Assuming this information is accurate, what I'm interpreting that to mean is that, for your purposes, Chakram would still be considered a "Hatred spender" regardless of the fact that it actually generates Hatred when used with the quiver.

So, in the context of the Marauder's 6-piece set bonus, your Sentries would still fire Chakrams. Likewise, it would follow that the new 2-piece bonus would not apply to Chakram, since it's still classified as a "Hatred spender" despite the added effect from the quiver.