I don't really understand what makes Lorenzo tick. As you said, when he is on his game, he is the fastest out there this season IMO. I don't think Rossi has really been in his head for quite sometime. Whatever gremlin is in Lorenzo's head is self-borne.
What would convince me to change my mind re: Lorenzo v Rossi is for Rossi to outqualify Lorenzo. Rossi immediately gets in trouble when Lorenzo outqualifies him since Lorenzo always has good starts when he is out front and pulls away almost immediately. Also, has Rossi beaten Lorenzo in a dog fight this year? I can't recall.
No good battles between them this year.
It has been very interesting to see MM and VR battle this year. Until this season I hadn't seen MM truly tested, normally he just checks out and rides by himself. His riding ability is phenomenal but his race craft is not there (yet).
JL has been around longer than MM but his race craft still doesn't hold up against VR. In a dog fight with either MM or JL if they're both running the same pace, my money is on VR.