Try

gthumb

It is a powerful image viewer with many awesome features. I'm not sure if it can show the data next to the images, but you don't need to add a library.

If you enable the side pane in eog (View menu - you can get this info at the side as well.

To enable this btw you need to have the exif display plugin enabled in preferences. If you do not have this plugin, install eog-plugins .

What I don't like in this renaming method is the colons used in EXIF date and time stamps (e.g. "2013:09:03 20:55:09_IMG_0108.JPG") which might create problems when transferring these files later to other environments (e.g. Windows).

You could run the naming scheme through sed, to replace the colons with dashes and spaces with underscores, like so:

mv -i "$i" "$(exiftool -CreateDate "$i" | awk -F ': ' '{print $2}' | sed -e 's/:/-/g' -e 's/ /_/g')_$i"

As for making the whole thing lowercase, you could use rename:

rename 's/(.*)/\L$1/' file.JPG
##  or
rename 's/(.*)/\L$1/' *.*

Or you could do it within your script using sed, as in:

j=$(echo "$i" | sed -e 's/\(.*\)/\L\1/')

...and then use the $j variable in place of the final $i of your mv line. This sed way is slightly more portable (if that matters to you) as different linux distros have different rename commands, while sed is universal.

Or, alternatively, the script can be modified as follows to perform filename conversion to lowercase at the beginning using tr instead:

for arg 
do
  tmp="$(echo "$arg" | tr '[A-Z]' '[a-z]')"
  mv -i "$arg" "$(exiftool -CreateDate "$arg" | awk -F ': ' '{print $2}' | sed -e 's/:/-/g' -e 's/ /_/g')_$tmp"
done

To perform slightly different commands for different file types, a bash case statement can be used in this script. For example:

#! /usr/bin/env bash
for filename in ./*
do
  tmp="$(echo "$filename" | tr '[A-Z]' '[a-z]')"
  case "$filename" in
    *.MOV|*.mov) 
      mv -i "$filename" "$(exiftool -a -s -CreateDate-tur "$filename" | awk -F ': ' '{print $2}' | sed -e 's/\-[0-9][0-9]\:00//g' -e 's/\+[0-9][0-9]\:00//g' -e 's/:/-/g' -e 's/ /_/g')_$tmp"
      ;;
    *.JPG|*.jpg)
      mv -i "$filename" "$(exiftool -a -s -CreateDate "$filename" | awk -F ': ' '{print $2}' | sed -e 's/:/-/g' -e 's/ /_/g')_"$tmp""
      ;;
    *)
      echo 'Not a *.jpg or a *.mov!'
      ;;
  esac
done

In this example, renaming of MOV files that have CreateDate timestamps ANY NUMBER of hours AFTER OR BEFORE JPG files is adjusted by using another (-tur) EXIF data and removing that that time difference suffix, and it might be necessary to change -tur part according to the location set in the system.