Bound but unused vertex buffers affecting the input layout?

I have a questions regarding vertex buffers and input layouts.

My mesh drawing code is essentially like this:

void DX11Mesh::Draw()
{
    mContext->IASetVertexBuffers(VertexBufferSlot::VERTEX_BUFFER_SLOT_POSITIONS, 1, &mVertexBuffer.p, &gPositionStride, &gStaticOffset);
    if (mNormalBuffer)
        mContext->IASetVertexBuffers(VertexBufferSlot::VERTEX_BUFFER_SLOT_NORMALS, 1, &mNormalBuffer.p, &gNormalStride, &gStaticOffset);
    if (mTexcoordBuffer)
        mContext->IASetVertexBuffers(VertexBufferSlot::VERTEX_BUFFER_SLOT_TEXCOORDS, 1, &mTexcoordBuffer.p, &gTexcoordStride, &gStaticOffset);
    if (mTangentBuffer)
        mContext->IASetVertexBuffers(VertexBufferSlot::VERTEX_BUFFER_SLOT_TANGENTS, 1, &mTangentBuffer.p, &gTangentStride, &gStaticOffset);
    if (mHasBones)
        mContext->IASetVertexBuffers(VertexBufferSlot::VERTEX_BUFFER_SLOT_BONE_WEIGHTS, 1, &mBoneWeightBuffer.p, &gBoneWeightStride, &gStaticOffset);

    mContext->IASetIndexBuffer(mIndexBuffer, DXGI_FORMAT_R16_UINT, 0);
    mContext->DrawIndexed(mNumIndices, 0, 0);
}

Say the mesh has all the components (POSITIONS, NORMALS, TEXCOORDS, TANGENTS, BONE_WEIGHTS) but in some pass (like a shadowmap pass where the input layout only specifies the POSITIONS and BONE_WEIGHTS) the other vertex buffers (NORMALS, TEXCOORDS, TANGENTS) are still bound.

1. Will each vertex still load those (unused) buffers, negatively impacting performance?
2. Also does it make sense to "unbind" the vertex buffers after use? for example Mesh1 uses bones but Mesh2 dosn't, yet BONE_WEIGHTS will still be bound during Mesh2 pass.