Part of why I switched to emacs was something called helm: https://tuhdo.github.io/helm-intro.html It fuzzy matches almost anything: files, function names, or commands

Project grouping in the traditional sense can be done with projectile and NeoTree. http://projectile.readthedocs.io/en/latest/ https://github.com/jaypei/emacs-neotree/blob/dev/README.md

I think what you are describing in the second half can be handled with company mode and triggering a major/minor mode off a file extension. https://www.gnu.org/software/emacs/manual/html_node/emacs/Ma...

http://company-mode.github.io

If that's not it it's possible Googling will find exactly what you describe. People tend to port anything useful from any editor to emacs.