Objects Linking and Actions

I created a character (‘puppy’) and added to it a few shape keys for things like smile, close eyes, etc.

I saved the character as puppy.blend.

I created a new blend scene and linked the ‘puppy’ object to this new scene.

What I now want to do is to create shape actions (in this scene) using shape keys from
the puppy object. The shape keys from ‘puppy’ do show up in the new scene, but they are greyed out and
blender doesn’t let me change their values in the shape key editor.

I turned ‘puppy’ into a proxy. That didn’t solve my problem - the shape keys for the new
puppy_proxy object are also greyed out, but now the modifiers for puppy somehow were
deleted. So now I have two problems (modifiers gone) instead of one.

What am I doing wrong??

Thanks in advance!

Oh, by the way, I’m using version 2.7

Would any kind soul bother to at least give me some kind of hint?

Since no one seem to be helping, I’ll start helping myself and answer my own question(s) Apparently a linked model can’t be modified at all. For instance, one cant tweak the modifiers of a linked model. Meaning, one cannot, say, adjust the subdivision level of subsurfs (looks like a flaw in blender’s workflow design?) What can be done : A model as well as its associated armature can be linked and then the armature must be ‘proxied’. That allows the user to animate the proxy armature which in turns controls the linked model. However, accessing the shape key values of the underlying model is still not possible. The workaround for this is to add more bones to the armature, add drivers to the shape keys and link the drivers to the new bones.