Test render passes, render settings in Maya

I've been adjusting the size of the branches of the tree, compared to the green screen footage and the icemen. If the icemen are too large they take on human scale proportions, which is confusing both from a storytelling point of view and a scaling point of view within the scene. If the icemen are small - almost the size of a small snowy icy drift caught in the branches we, as the audience, will upon first glance ask ourselves  'what are they? ice formations? men? characters? figments of the woman's imagination?'
With scaling the entire tree and associated textures, the render was slow. In 'dressing' the tree to shot (cutting off any unnecessary branches) the render time is signifiantly reduced.
I have the original tree file available for any mid to wide shots in other scenes.
This will require a new UV map, for these particular branches; the screen shots below show where the UV map is now incorrect (indicated by blurred sections on the branches).

Yesterday I had a one to one with Sang-Yu, to double check all the render settings and passes, before I get stuck into the animation
Below is a recording of the tutorial, showing the setting up of the render layers and then the render pass settings...

Setting up the associated multi-passes in render settings, and creating a duplicate render layer of the master layer.

New tree section requiring a new UV map; with the reflection multi-pass window