JobRoller offers all of the features you listed in various forms:
• Register - Yes, WordPress user registration functionality
• Submit their resumes and manage their info and criteria - Yes, Job Seekers can input their resume and manage this through their dashboard
• Follow job categories - Job Seekers can use job alerts or subscribe to the RSS feed for specific categories
• Search jobs by various criteria - Users can use the search fields and "Browse by" options to search for jobs
• Maybe add jobs to a que of positions they are interested in - Job Seekers can "star" jobs as favorites which appear in their user dashboard
• Get notified when new jobs are posted to those categories - See response to "Follow job categories"
• Request to be considered for them if they so choose - Job Seekers can apply for jobs on the job listing page
JobRoller does not currently have a built in import tool, so importing data would likely involve some knowledge of mysql admin in order to ensure information is migrated into the correct location, particularly as JobRoller uses WordPress custom post types, and listings are not regular "posts". Thanks.