For me importing svg files works OK (debian), outside a little module import bug I fixed now. I think the GUI part of file import is common to all open/import operations in FreeCAD, do other filetypes (.fcstd, etc...) open correctly?
About the imported files not displaying correctly, usually when you get a shape that only display points, it is because a face got created but has a problem that prevents it from rendering correctly, for example edges crossing each other. If you can attach the file here (you might need to zip it for the forum to accept it) I can have a look if you want. But in general terms, the svg importer is not much used, so it has still a number of bugs, probably.
The hard-coded precision and other things of that nature are mostly due to my inexperience in coding, specially at the time I did that part. There is now an internal precision setting in the Draft module, I just updated the SVG importer to use it.
About line segments, my own use of imported SVG files is mostly for architecture drawings that come from pdf files that I converted with inkscape. So it is important for me to have lines, and sometimes inkscape produce bezier segments that are totally straight. But honestly I didn't venture much into the whole bezier curves world, the current support is very rough, as you saw.
In any case if you would like the svg importer to behave another way, it would be fairly easy to add a setting in the preferences, so users can choose which way they prefer.
If you want to work on this, feel free to do it, I'll include your changes. I'm pretty happy that someone else looks at that code actually...