Yes, you should absolutely contact your HR representative or your former boss to see whether you would be a good fit for the job you are interested in.  Depending on the circumstances for your departure and there are no restrictions built into you returning to your former company, you should be able to apply for a job with your former employer as long as you left on good terms and you are eligible for re-employment.  Most companies usually post openings for employees who are subject to layoffs but when that is not the case then, it’s up to you to do your homework and definitely follow up if there is a job that interests you.

Under no circumstances should you ever answer personal questions on an interview no matter how “informal” the interview was intended to be.  Recruiters are smart and they will try to find out as much about you hoping you will divulge some details of your personal life that can be used to disqualify you from the running.  Do not become friends with the recruiter until AFTER you receive a job offer.  It is not appropriate under any scenario to have a personal conversation with someone who is in a position to offer you a job that you do not already have a relationship with.  Be careful of falling into the trap because that is exactly what this is.  Do not be fooled that the recruiter finds you irresistible or wants to build their FB list because they don’t.  Stick to questions and conversation that only talk about your qualifications for the job and nothing more.

Chances are recruiters are very busy either screening, sourcing or interviewing for open positions.  If you had an expectation set that the recruiter would contact you then by all means follow up to find out what the status of the search is.  If you’ve made every attempt to contact the recruiter and they still have not responded, chances are you did not get the job and it’s time to move on and apply your efforts elsewhere.

Not unless you’ve tried every other option available to you.  Hiring a recruiter who takes a percentage of your salary if they place you instead of charging the employer is a model that exists in most industries.  However, unless you know someone who got their job through one of these recruiters and can attest to this, I would be very cautious in proceeding because there are many people out there who are claiming to be “recruiters” who say they can get you a job and they can’t.  In no way should you pay up front for any services for a recruiter claiming to get you work. Ask to see their list of placements and references you can call to verify before you engage the services of a paid recruiter.

Recruiters are busy, busy, busy, even when they are not actively recruiting!  It’s hard to make time for follow up with every candidate even if they thought you were qualified for the job.  That’s no excuse for good manners however so if you’ve asked for feedback, followed up and still have gotten no response, chances are you 1) are not in serious consideration for the job; 2) they’ve made another hiring decision; 3) just too busy to let the candidates know the status of the job.  In any case, you need to take responsibility and either decide to keep pestering the recruiter which may not bode well for you, or just give it up and move on to the next job.  There are plenty of other jobs out there so don’t stay stuck wondering what happened.