Comic book artists work for a living. They work hard and the hours are long. Don't fool yourself.
You will generally have two weeks to finish twenty two pages and sometimes less. Your enemy is "the deadline" because if you don't make it to the line on time, your dead (professionally).
Editors want to know if you can do what they need, not what you want.
Here are my recommendations:
-Take out the colored work. You are applying to be an artist, not a colorist.
-Take out the portraits (face shots) and Disney drawings. Unless you are applying to Disney directly. I understand you want to show a diverse portfolio but you will distract from your work as a comic book artist.
-Do your Batman panels look like they are directly from Greg Capullo's work? You are not Greg Capullo. Do not submit work that is copied from another artist. They will bust you on that.
-Cover artists are specific in their genre, it's ok to throw some splash pages in between panel work but not a lot.
-Create three sequential pages with an original idea or a script. Skip the fight scenes, no double pages, very few single shots of the hero.
-Do not use heroes from other books when submitting to a rival company.
-Show you can draw crowd scenes, cityscapes, cars, interiors and quiet moments.
-Specifically show you can repeat faces in different scenes and have them look like the same people. (that's a big one)
-Create dynamic poses and your anatomy must be good. Use websites like PoseManiacs.com or Scott Eaton's Bodies in Motion.
Pick a script, use three pages and attach it to your portfolio with the panels to show you can read and follow the writers concepts.
Use free comic book scripts for practice. Here is a script archive: http://www.comicbookscriptarchive.com/archive/the-scripts/
Use The Definitive List of Comic Publisher Submission Guidelines. Find out exactly how to submit to each publisher in the method they prefer.
Successfully Submitting Your Comic Book Art Portfolio