Why do meow-append and meow-insert behave the same way when there is no region?
In Emacs cursor is located between two characters, so we would have to implement a hack to change the behaviour. You can read more about it in this discussion thread.
I encountered a weird command behavior in normal state
Meow’s internal command will not call Emacs’ commands directly. They will call a keybind which is then linked to a command. Your customized keybind might be overriding the original command. Lookup the command you want to execute (meow-var.el) and overwrite it in your config.
Example:
Here you can map Delete character to internal Meow’s delete character function.
(setq meow--kbd-delete-char "<deletechar>")
Can I use meow in doom-emacs?
Yes, please check out doom meow module.
Can I have a major-mode specified local leader?
No, you can’t. Here is the explanation.