How to add a new column with custom value extracted from the job?
From what I can tell you can definitely customize the columns for a custom view (I can't find where to change it for the "All" view, but it's probably possible).  Unfortunately it doesn't look trivial to add a custom column without writing a plugin, for example the jacoco plugin:

https://github.com/jenkinsci/jacoco-plugin/blob/master/src/main/java/hudson/plugins/jacococoveragecolumn/JaCoCoColumn.java

Jenkins Java Doc:

http://javadoc.jenkins.io/hudson/views/ListViewColumn.html

Edit: This plugin might get you closer to what you're looking for:

https://wiki.jenkins-ci.org/display/JENKINS/Extra+Columns+Plugin