I've been using emacs for ~15 years. I don't now what is considered lean. My init is 343 lines. Probably removing all the comments and junk collected over the years it is likely ~200 that actually does anything useful at this point, I should probably clean up. I use emacs everyday. I get the desire to want to do everything in emacs but I also don't. It is good at what it does, it happens to do other things too but I don't know if that is the best way to work.