Precision Editing Of Motion Path

There are no controls for that purpose or for specifying exact length, nor does PPT 2011 offer Pixels as a measurement unit.

What may help is to position Static Guides & use them to establish the path length.

Tried that and found manually positioning the motion path never got it spot on. Even then, I could not find a way to copy and paste the motion path. 

I read about doing the animation backwards and starting at the end point. Whatever I do, I get the first left movement ok but I'm then stumped. 

Googled PowerPoint animation timeline but that just came up with infographic solutions not editing tools.

As you can probably guess, I'm a newcomer to PowerPoint animation.

The path itself is just a special case of a line. Copy and paste is supposed to work, but in PPT 2011 with Mac OS 10.10.5 it seems impossible to select the motion path line. 

I was able to copy the path by saving the presentation, quitting PowerPoint, opening the presentation again, then selecting the shape (rather than the line), switching to the Animation tab of the Ribbon, then copying the shape and pasting the shape. The associated path was also pasted. That's a lot of work to do for a simple copy/paste.

In 2016 copy/paste worked as expected. Since 2011 is going bye-bye I don't expect Microsoft to fix this problem in 2011.

Animation is simple in concept, but there are endless combinations you can have. You can have one animation end and be immediately followed by another by choosing After Previous  for the second animation.

It sounds like you have the basic idea down. Here's a tutorial (unfortunately using WIndows PowerPoint, but the Mac version has all the same commands laid out a little differently):

https://www.youtube.com/watch?v=P9ftw1rHLk8