Well, here's my $.02, for what it's worth. I'm not a lefty, but my dad, father in law, wife, sister, and daughter all shoot left handed, so I get to see what works for them. My dad prefers lever actions and semi autos, since he grew up before left handed bolt actions were commonly available. My sister doesn't like lever guns, but they wouldn't bother her as much if she would just button her shirt up a little higher. Hot brass seems to distract her when it's caught in her bra, so she especially doesn't like lever guns like the Winchester '92. My wife likes lever guns, but she dresses more modestly, so even the '92 is no problem. I have my daughter hunting with a single shot, mainly as a way to keep weight down for her. Even her 4.25 pound Contender carbine gets heavy after a long day, since she's only about 60 pounds.
The down side of lever guns and semi autos for lefties is definitely safety. If you have a case seperate, or some other kind of high pressure/brass failure event, the rifle will allow some of that to vent out the right side of the rifle, straight into a lefty's face. Be extra careful, if you reload, and use only quality factory loads if you use store bought. Even top eject lever guns can spit some gas out the loading gate and such. I had it happen with factory loads, once, and it made me glad I'm right handed, with my face on the safe side of the receiver.