Jtest has fully functional command line interface so generally integration should not be a problem.
As for your questions:
1) there is a Jtest plugin for Maven, so you will be able to trigger your post-build action easily. It's thoroughly described on http://build.parasoft.com .
2) you can specify the Test Configuration of your choice by using -Dparasoft.config option (i.e.: mvn parasoft:jtest -Dparasoft.config="user://Unused Code").
You can find all the parameters which can be used with parasoft:jtest goal described here: http://build.parasoft.com/docs/maven-parasoft-plugin/jtest-mojo.html .