I've never understood why people think that fingering is more complicated than bowing; in my own experience, and that, I'd say, of almost everyone I've ever talked with about it, it's quite the reverse, except for beginners, and the same is true of instruments like the guitar (unless your ambitions don't go further than strumming). Mind you, I speak generally; I don't doubt there are styles in which bowing is less important (I don't want Jeri to beat me up) but I haven't experienced them.

It's relatively uncomplicated to set up a standard guitar for left-handed playing (though that will depend to an extent on what sort of bridge it has), but a fiddle has to be built specially, or radically altered, due to the positioning of the bass bar and the way the table is thicknessed. Just reversing the strings won't do the sound any good, and will eventually damage the instrument.