There's no requirement to like rangefinders, even if certain of them are "legendary." They are just different, a different way of looking, and so it might suit some people and not others. Similarly, many people find a waist-level finder weird the first time they use one, some grow to love it, and some never do.
I am not sure if the issues described by the OP fall entirely into imperfections (less accurate framing), or limitations (having only one lens for the system), or if they're a combination. Sometimes, the way to use or benefit from a system is to accommodate to its limitations and use them, rather than trying to work around them. For a small example, it can be a useful discipline to use only one focal length for a day and just see the way it sees, rather than continually changing lenses or zooming.
Viewfinder issues can be real in rangefinders - even Leica-philes divide over which viewfinder magnification they like. I know in a thread like this, everyone suggests their own different piece of kit, so as another distraction: I think one of the best viewfinders is in the humble Konica auto s2 fixed-lens RF. It has a nice large VF with parallax corrected frame lines, a good 45/1.8 lens, and doesn't cost much. The meter is often dead by now, but it works fine in manual mode, and if you're used to a separate meter that's not a problem.