I really missed this feature in a recent project. There were ones on aescripts.com that did parts but not all of what I needed, so I combined some of them to recreate the F5 key for AE. The script shifts layers that occur after current time and pushes the end markers/keyframes for those that are on.
You can download the script here:
https://code.google.com/p/smdcode/downloads/detail?name=AE5.5%20-%20Add%20Delete%20Frames.zip&can=2&q=
If you need a better description of the script it’s been posted here:
https://www.smartinteractionlab.com/painless-frame-addingdelete-in-after-effects
As I mentioned, I combined a bunch of available scripts to do this, so special thanks to:
Filip Vandueren for FV_selectALLfollowing.jsx
Paul Tuersley for pt_ShiftLayers.jsx
Lloyd Alvarez for LayerHandles.jsx
– Ben