I agree that he should have nom'd Dani at the get-go if he was going to do it, as it made no difference if it was his intent. The only reason I can see not to is that if she won the veto, he would be able to say that he didn't go after her and kept whatever kind of deal he made, but if she didn't win, he could nom her. Whereas if he nommed her and she won veto, that left Jeff with nothing but a failed attempt. I imagine that was Dani's thinking with Brendon. He could have lucked out and played veto and won, and then she could have said she was honoring their deal.
Obviously none of these guys feel bound by their word or promises, so it's almost a joke to see them talking deals about future performance in return for protection in the week at hand.
Re Porsche -- I did catch a little of Showtime Thursday, tuning in to see who won HOH, and Porsche and Kalia seemed 100% they were going to be on the block, as soon as Jeff won HOH. They seemed to know it would not be Dani up there. Porsche was saying she didn't want to leave without winning a single competition.
It couldn't have helped her that she (and Rachel) came in second.
I think that with Dani gone, Porsche will do whatever she can to float back to the other side. Kalia and Porsche are not a force to be reckoned with. They are more the annoying mess on the floor that gets swept out when you clean up after the showdown with the real player (Dani) is over.