No, it will probably go to "Documents", and if you hit tab again it should go to "Downloads". (Assuming you have the normal default folders)

bash's autocomplete fails (at least with default settings), but e.g. zsh can figure out what you mean

Not with a decent autocomplete. It will look for a folder starting with a small d and if it doesn't exist it looks at a folder with a large D.

No. Zsh. It's pretty easy to have a nice auto compl. No need for omz. After knowing poweline10k I just use it and syntax highlight plugin, manually installed. There is no need to add entire omz.

I use fish which is quite nice OOTB, although if you want a posix compliant shell, zsh with some plugins is also great.

https://ohmyz.sh/

Zsh.

Omg looks like people think omz is a shell.

I personally like xonsh despite the minor amount of wonkiness it has, it's so nice to have python available directly in your shell, it takes the "i don't care about the quality of my code i just want this shit to work with minimal effort"-ness of bash and turns it up to 13.