I tend to think that if Pete succeeded in killing himself, that it would have hung over the Beatles like a black shelf cloud. I can just imagine people yelling "You killed him - you Beatles did!!"
You know how people are. It's crazy but, yeah, I think that would have happened.
I think Mona Best accepted the firing because she once said there were no hard feelings for the Beatles. Although Pete was her son, I think that Mona may have secretly realized that Pete wasn't a right fit for the Beatles. Pete had said in his bio that he shared in their legacy and by rights he should have benefited from that legacy. But how? Without being their active and current drummer, he had no claim to a legacy with the Beatles. I mean should they have sent him an honorary paycheck periodically because he was entitled to share in their legacy?