SLRs are way more versatile than rangefinders, but you shouldn't worry. I've always bought SLRs with multiple exposure capability and depth of field preview, but I've never actually used either feature.
With an SLR, you have the advantage that you're looking through the lens (and can see the effects of graduated and polarising filters, and the depth of field - if you can preview it by stopping the lens down).
With a rangefinder, you have the advantage that you don't have to look through the lens. There's no blur in the finder (and you don't get annoying dust specks everywhere). And if you use a yellow filter - or a really dark infrared one - your view isn't obscured as it would be with an SLR.
While you can't see depth of field through a rangefinder window, you should know by intuition, experience or the depth of field scale on the lens what you're going to get. And a lot of new SLR lenses don't even have them. I used to shoot with an SLR all the time, with a 35mm lens. I'd choose to shoot at 1.4 or 2.8 or 5.6 purely according to the effect I wanted, or according to the circumstances - e.g., want selective focus but subject moving a bit, so I'd go to 2 or 2.8. I didn't find the time to stop down and preview DOF.
This all comes much easier if you don't use a zoom and just get to know a few focal lengths.
So my experience was that I was using my SLR pretty much like a rangefinder, and since I often focused in very low light and preferred wider angles and wanted a more compact camera, a rangefinder became the obvious choice.
I've never found a huge difference between the two - though I can see the point of Bill Pierce's article - it's just that if you shoot to the strengths of an RF, it's far more rewarding than an SLR.
About preferring wider angles. First, RF wide angles tend to be better than equivalent SLR wides (price, focal length, aperture, make, newness, etc.) because there's no mirror box to clear. My Zeiss wide probably gets well over an inch closer to the film than my Nikkor ever could, for instance. Second, though viewfinder magnification is better in an SLR for longer lenses, it works in your favour for wides, because the magnification doesn't drop on an RF.
You'll probably futz around the first time you try and focus an RF, but I remember doing that with my first SLR.
One last thing. While there's a lot of mystique around rangefinders - at least the ones that come from Germany - rangefinder-focusing was the bog-standard way to focus a camera back in the 50s and 60s, and millions of folks who only took pictures at holidays and at Christmas seemed to manage it perfectly well. Don't know much about your Olympus, but it would have been one of those cameras.
One very last thing. A friend of mine took a Zorki on holiday, knowing nothing about photography. She just followed the exposure instructions on the inside of the film box, and everything came out perfectly.