Then you are associating yourself with the world's unluckiest people, who ostensibly also have the world's worst taste in women. Your friends, if the allegations were indeed false, are living, breathing statistical anomalies. Either that or they indeed did commit whatever the sexual misconduct was/abuse their partner. If they did, why would they tell you? It would make them look like shit.

It isn't a common thing. Like I said, most people you talk to will have never met anyone it's happened to. 99% of the time people will go their entire life with never meeting someone who has ever met someone who it's happened to.

Again, it would be like not eating because you might choke, or not driving because you might get in an accident someday.

Edit: I don't know the statistics of false domestic abuse cases. I'd wager it's a bit higher than rape allegations, but that's not what we're talking about.