vim-rsi VS xcape

that however may lead to suffering. You will have to change a lot of defaults and this can make you unable to work with default Vim. Try out https://github.com/tpope/vim-rsi and see if that will suffice.

I use vim.rsi by te legendary tpope.

You can you this plugin to get the same mappings in insert mode for Vim:

https://github.com/tpope/vim-rsi

You may be able to emulate it with cnoremap. See vim-rsi which is the set -o emacs version of what you want (but it also applies in insert mode).

I heavily rely on tpope/vim-rsi, which will provide you with to hop to the end of the line in insert mode

Look no further than the vim plugin master himself, Tim Pope: https://github.com/tpope/vim-rsi

I would just define whatever "standard text-editing keyboard shortcuts" you want in insert mode, and then just use insert mode as your "vim for note-taking". Kind of like Tim Pope's RSI but with the "standard" key bindings you want instead of bindings based on Emacs/readline.

Don't know about i3, but you can achieve this in Linux/X11 using for example xcape: https://github.com/alols/xcape

I guess that xcape is what you're looking for.

You can use xcape (I assume xorg only; https://github.com/alols/xcape) to set any key including super/meta to trigger a custom keyboard shortcut on release.

Caps Lock is both Control and Escape depending on whether you hold or tap it. I use xcape.

All you need is dual mode modifiers - remap your spacebar to act as Ctrl when pressed and generate space symbol when released. You can make it with xcape on linux and with dual-key-remap on windows. It is also something for macos, but I never used it.

I have the same setup on linux. Using xcape and xmodmap together.