I'm using Nemo, but could switch to another file browser compatible with Fedora + Cinnamon.

I've turned off previews/thumbnails, but a lot of odt, jpg, and sometimes pdf files still show previews/thumbnails, and the rest all look alike regardless of type.

Is there a way to get distinctive icons for each file type, instead of having to check the full file name?

Also I've attached some text strings such as "(Calibrized)" (sic) showing important status information (i.e. that I've imported a copy into Calibre; I've chosen that term so I can search for it without picking up references to something being calibrated).

Is there a way to add some colored indication when the filename includes these terms? I know Linux doesn't support MacOS or Windows tags, but using file name strings could help cover some important tags.

spacefm shows filetypes ( most do ), dont know of any common linux fm's that can add colour labels.
Maybe try installing a better icon theme, not all icon themes are complete so you end up with 'generic' icons.