Automate video production with After Effects CC I am tasked to produce ~100 videos of 10 minutes in After Effects. The videos will later be commented by voice, and I am tasked only to make the "motion" part.

Each video use:


about 30 "image" scenes (5s): an image is being slowly zoomed in
about 50 "footage" scenes (10s): a footage is being shown for 10s
A few other misc. animations (intro and conclusion with logo)


In each new video, I need to change:


The 30 images 
The 50 footages (I will be given links from Youtube along with the timestamp like "0:16 to 0:26")
A limited amount of text, here and there


I plan to make the template first, and I was wondering if you guys knew a smart way to program each video (ie auto-replace the 30 images, the 50 footages and the predefined text, then build and go on to the next), a bit like "mass-mailing" for instance.

They say in programming, "if you have to do it more than 3 times, program it"... I think 100 applies! However, being unfamiliar with After Effects, I do not know where to begin! Guidance will be much appreciated.
You could achieve a certain automation by creating precomps for each clip. Then, drag every alternative file into each precomp and just stack them on top of each other. Now, apply the motion effect (the zooms etc.) to the precomps instead of the footage directly. That way, you can just hide the top layer to that the next image is visible, on which the animation will automatically be applied since it sits in the same precomp you animated before. Alternatively, to make the process even easier, you could script an expression that looks at the index of each layer in your precomp and hides every first layer for every comp, or every first and second, etc. etc. When it comes to the scripting of it though I must admit that this would require a few hours of thinking on my own, so maybe someone smarter can help you with that :D