I will implement animation blending as the next feature in my skinned mesh class

Just a suggestion, depending on how you implement your skinned mesh class, you may want to consider making an animation controller as a completely separate class. That is, if your skinned mesh class is closely tied with file importing (which it shouldn't be, but that's another story), a separate animation controller can be used with any appropriate skinned mesh. All the animation controller cares about is calculating animation stuff and storing the results somewhere. Rather than having the animation controller get tied in with bone transforms and offsets, etc., just have the animation controller calculate all the animation transforms and store it according to a provided bonename-versus-index array or other simple interface. I have one animation controller that takes an array of pairs <bone-name, pointer>. After it calculates an anim transform, it looks up the key-frame-name in the array and stores the transform in the address provided (which happens to be with the node with the same name in the hierarchy.) That array is static, needs to be filled only once, and lasts the lifetime of the controller. Then the skinned mesh class, which knows all about what's needed to get the shader setup, takes the anim transforms (which magically appear in the correct place after the animation controller is told to "advance the time") and handles the remainder of the process.

That approach separates the skinned mesh from having to deal with multiple animation sets, which sets are active, how they're being mixed, what time that sequence is in which animation, etc. On the other hand, the animation controller doesn't need to deal with transposing or finding nodes in the hierarchy, or anything about offsets, etc. I.e., keep all the pose position info in one place, and all the animated position stuff in another, and relate them only though the node-name.