To maximize your chances, interact with a number of agents and maybe one or two will stand out. Do not sign a contract unless you are convinced that you have found the right agent for you and DO NOT accept a referral from a lead generation company that randomly sells your contact information to an agent who them has to pay them for your information.
some agents require you to sign an agreement that you are working with them exclusively others dont... But I highly recommend that you work with someones whos personality you can relate with. Dont put so much influence on the little years or so many years that an agent have been on the job. we all have access to the same information. and everyones work ethic is different.
I wouldnt put to much thought on a fulltime or parttime Realtor either.... if someone wants to work for you and you can relate with them ....trust me they will do their best for you....... most realtors for the most part are ready to do a great job for you.