I think that from your points it already shows fairly well, that it is most likely not going to do you a service to continue this in the long run.
Tremendous increase of the chances of being hired.
Yes, in the short run it may help you get your first job, or to get back to the job market after a long break... but what after?
First of all, the effects of having a low salary and no or low raises are cumulative. If your colleague starts out with the exact same salary but gets only 1% higher raises each year, the net effect of it over 25 years is that he will have over 27% higher salary. Now if he already started out with significantly higher wage, the difference is going to be even bigger.
Even if you feel you don't care about the money now, it may - and probably will - change in the long run. You are going to have different phases in your life. You may become a family man, at which point your salary is going to become significantly more important to you and your beloved. Also at some point you will need to start thinking about - and maybe saving for - your pension years. If not thinking ahead, at that point you will have already lost many years of cumulative growth potential.
The employer sees you as a person that is not occupied by money, and are really sincere in your work.
That may or may not be the case, as you yourself list other possibilities among the disadvantages. Moreover, not being occupied by money does not necessarily mean that one really cares about his work and is good at it. So if you want to give the impression of someone who is so passionate about his/her job as to not think about anything else, I believe a positive approach is better: tell them about what you do feel important in your profession and how that shows, instead of stating what else you do not feel important.
My personal feeling is that if you tell you don't care about money, employees in general are more likely to see you in a disadvantageous light. Or both, at best: they may acknowledge you are so passionate about your craft, and at the same time be happy to exploit you via cheap wages, as long as you are willing to take it.
I think it is important for you to realize that in the long run, you owe your own personal and professional reputation to ask for a decent salary for your good work. If you do a great service to your employer, solving their problems, you are actually earning / saving them hard money, so it is only fair to get a decent pay in exchange. No need to go overboard of course, but if you yourself don't represent your own interests, noone else will.
Not caring about the money, or even working for free, may work though if done for a relatively short and concrete time interval, and as part of a longer term plan. So if you want to get your first job as a newbie, to get experience and build reputation (with which after a couple of years you will be able to get a more decent job with a better salary), it's fine. Or if you desperately want to get your dream job at a dream company, you may decide to offer them your services cheaply or even for free for a well defined trial period, let's say 3 months. That should be enough for you to demonstrate them your real value, and then negotiate a full employee position with proper salary. Or get quickly fired after being exploited, if they don't actually want to treat you fairly... there is always the risk. By limiting the length of such an experiment in advance, you limit your potential losses too.
