Inputting live screen recording into After Effects

For a time there was a plugin called "Lens Feed" by Frischluft:

https://www.frischluft.com/lensfeed/index.php

It was great, I used it to add teachers into still frames of movies as you could move the camera and lighting to match exactly.  This was only for previewing of course.  

These days, you might be best looking at preparing your animations in advance in AE, then exporting the clips and bringing them into Adobe Animate.  I used this when it was Flash and you can bring in cameras as layers.  If you set up everything correctly with keypresses to trigger the animations, then you can have them run over your live video.

Or... last option, you could fake being live.  Record in advance, add your animations and then play out the video.

No and no. This is simply a long standing limitation due to how AE treats footage and only updates stuff based on how the time in a comp changes. It only works the other way around like funneling AE's preview onto an external device like Blackmagic cards and such and then using their software or other live tools like VJ-ing tools to manipulate the output further.

Mylenium