Don’t know about Level 4, but Levels 1 to 3 are amenable to solution using your emacs scratch buffer. Elisp has 98% of what you need.
I love Emacs, but I never invested time into becoming proficient with Elisp. Do you have any favorite functions or patterns that you find really handy? Would love to add a bit into the post about some cool things you can do in Elisp.