Bash keybindings that match those of gedit?

There is some information about key-binding in this bash reference manual.
To edit key bindings in gnome-terminal, go to Edit->KeyBoard Shortcuts.

While I'm not convinced that what you want to do is absolutely impossible (this is linux after all), I do believe that it will turn into more trouble than it's worth. Editors and shells are meant to be used for very different purposes and were designed with these very different purposes in mind. In the long run, I think you'll be better off learning how to use each tool as it was intended to be used (especially if you ever have to use someone else's computer). Switching between editor and shell becomes second nature with just a little practice.

Update:
As pointed out by djeikyb in the comments, bash does support vi mappings. If you are willing to learn how to use vi, that may be what you are looking for. Here is a quick write up on vi key bindings in bash, with cheat sheet.

This is impossible: on the one hand you have a terminal (which hosts a bash shell) and where - as you say - some combinations are already taken. On the other hand, you use gedit which doesn't allow changing key combinations.