In my experience (as a tax preparer for real estate agents), it is very, very hard to do this on a part-time basis and have it make any money.
Realistically, in my view, you need to sell (on average) four homes a month to make a decent living from real estate - one to cover the tax bill, one to pay your fixed license and other fees, and two to provide the profit you'll take as earnings.
Keep in mind that your fixed costs are a very large proportion of your earnings if your earnings are low (as in "part time"). You should be aware of all of those fixed costs before you investigate this much further.
Finally, there are a lot of people trying to make a living as part-time real estate agents. You will be competing with them, as well as with all the people who are established AND working full-time in the biz. And, given the choice, most people are going to want to work with someone who is experienced AND working in the field full-time -- kind of like how you don't want a plumber who's a lawyer on the side, or a teacher who also sells mutual funds a little bit, or a stay-at-home mom who dabbles in engineering design.
I think there are lots of things you can or could do part-time which have a higher probability of success. I personally think people entering real estate at this point is further evidence of a coming bust in real estate - like a form of
odd lot theory.
Sorry if this sounds overly harsh -- you asked for opinions, and those are mine.