I happen to know two wedding photographers who primarily use Leica Ms but then again I don't know a ton of wedding photographers.
Steady income? Depends on how you define steady. I certainly make a living, primarily through grants, fellowships and exhibitions. As a former breaking news photographer I'd say that I could cover about 80% of what I used to shoot using a Leica. There are some photographers, most notably
Angel Franco at the NY Times, who use Leicas quite often if not exclusively. I remember when things went digital he was pretty pissed about switching to Canon but now he shoots Leica again.
You're pretty young so my advice would be to focus less on "how" and more on "what." I don't recommend photography as a way to earn a living, there are better ways to do that. But if you love it and don't mind making less than your peers it's great. Figuring out what you want to photograph, or rather what you are passionate about is the key. I could shoot what I shoot using a SLR, point and shoot or any number of other things. For me a rangefinder is a better fit, especially since I shot with SLRs for the first half of my career. For you it might not be the case. There are pros and cons for every type of camera...