Ideally, I'd like to save the world.
First bit of advice: grow up. Be interested in research because you're curious, not because you're special and/or status-seeking. Until the word that comes to mind is "improve" rather than "save" you will be looking at the wrong questions for the wrong reasons.
Journals might be biased against freelance researchers.
Oh, absolutely. If you want to be part of academia, you have to be part of academia.
It might actually be better to spend some time doing research under others before doing it on your own.
I would replace "might" here with "would."
Oh, absolutely. If you want to be part of academia, you have to be part of academia.
I think this varies from field to field. Some fields are more biased than others. Math for example is not very biased in that regard. The hard sciences are not as biased also but in order for people to do good work in them they need resources that they are going to have trouble getting outside academia or industry. I suspect (but have no strong evidence) that the "softer" a subject the more likely the journalists are to discriminate based on whether or not a submitter is in academia.
Ideally, I'd like to save the world. One way to do that involves contributing academic research, which raises the question of what's the most effective way of doing that.
The traditional wisdom says if you want to do research, you should get a job in a university. But for the most part the system seems to be set up so that you first spend a long time working for someone else and research their ideas, after which you can lead your own group, but then most of your time will be spent on applying for grants and other administrative trivia rather than actually researching the interesting stuff. Also, in Finland at least, all professors need to also spend time doing teaching, so that's another time sink.
I suspect I would have more time to actually dedicate on research, and I could get doing it quicker, if I took a part-time job and did the research in my spare time. E.g. the recommended rates for a freelance journalist in Finland would allow me to spend a week each month doing work and three weeks doing research, of course assuming that I can pull off the freelance journalism part.
What (dis)advantages does this have compared to the traditional model?
Some advantages:
Some disadvantages:
EDIT: Note that while I certainly do appreciate comments specific to my situation, I posted this over at LW and not Discussion because I was hoping the discussion would also be useful for others who might be considering an academic path. So feel free to also provide commentary that's US-specific, say.