Questions[file-sorting](ubuntu)

I'm using Ubuntu 20.04 LTS and I want to sort files in a file explorer by their extension. I found the possibility of using nemo and sort the files by the Detailed Type but this doesn't really work satisfactorily. I have e.g. some files from MATLAB with the ending .m but some are marked correctly marked as MATLAB file but some are marked as Objective-C source code but they are also plain MATLAB code. Is there any way to sort the files (and folders) reliably by their extension? I'm not tied to any file explorer so any recommendation is very welcome. The two most important features which must be supported are

1. Sorting the files by their extension (highest priority)
2. Showing the whole address in the address line (rather than only those 'blocks' starting at the home directory)

According to Wikipedia's utf-8 Codepage Layout, its character-set is as follows:

! " # $ % & ' ( ) * + , - . / 0-9 : ; < = > ? @ A-Z [ \ ] ^ _ ` a-z { | } ~

But (excepting /), filenames beginning with these character are sorted by name differently:

! " # % & ' ( ) * + , - : ; < = > ? @ [ \ ] ^ _ ` { | } ~ 0-9 $ a A z Z

Why is this? Does it have to do with the file system? File Manager? Locale? Something else?

I want to sort file (with removing duplicates) which contains wordlist with a size of almost 25GB. I am using sort command in Ubuntu terminal but it takes hours to output sorted file, the command is:

sort -u input.txt>output.txt

Is there some alternative and efficient way to do the same?

I work in material science so many of my directories are named by chemical element or equation. As such, ls and ls -v list my directories out of chemical order. I know I could rename my directories so they start with the atomic number of the element, but I don't want to do that. I was wondering if there was a simple way I could provide customized rules to ls such that it would list the directories according to the atomic number of the element instead of alphabetic or numeric order. If there was an alternative to ls that would be acceptable too.

I'm looking to list the entire contents of a directory, including the contents of subfolders but sorted by filesize. Thus far I've managed to get as far as listing and sorting whilst still being recursive with ls -lhSR(the h is nice to have but definitely not essential for me, as long as I can get file sizes). I am likely overlooking something obvious, or asking the impossible, but any advice here would be greatly appreciated.