"I read where they cleared Black Cone but didn't see anything about Marble Peak Trail being cleared."
I thought I had submitted that trail report but it doesn't appear yet. In fact, that trail is passable, although there is the usual brush and a couple of tree trunks to cross.
"I was thinking of starting at China Camp to the Divide, then on to Black Cone Trail, Marble Peak Trail and then the Tony Trail into Tassajara."
You are accurate in your trail planning. That route should give you a great workout and wonderful views. I'd plan to camp at Pine Ridge Camp because it always seems to take a full day to cover the Black Cone Trail, even going "down" it.
Irritants to be prepared to accept? Face flies, ticks, poison oak and brush. But it will all be worth it!