Okay... an interesting exercise. Pretend I were a facilitator. You and your PI are in separate rooms. I'm hoping that you could perhaps answer the follow-up question (write it down for yourself; it's not so important writing it down here unless you want to)... then I'd like to see if any of the faculty posters (like Kelly) can pipe in with a response.
PV: "While I am almost there, I am not ready for a faculty position, with one first author publication."
Given this information and your previous indications of other papers you have published, what do you need to be ready for a faculty position?
Now swap papers with your PI. Begin conversation.
I did miss the fact you have been on
a mentored research award (K award) for the last three years. That is extremely important to know (because that MD time does make a little difference in the perception of one's readiness for a faculty position). If we're talking about your last two? years of funding, then the raise in your title should help, but I would also think you have to be in position to start applying for faculty positions "now" (before you hit year 4), at least to give you an extra year to really find out what you need to land a tt spot. Applying encompasses all aspects of networking/presenting your work at conferences, with "invited visiting lectures," and talking with other faculty members who could eventually be your paper and grant reviewers. Your communications skills need to be polished. Your scientific creativity and research critical thinking must be honed.
How well have you been following the mentoring plan which should be listed in detail on your grant? How has the plan met your needs, your PI's expectations, and your research?
What is important about the above question is to see the gap between what you think you need and what your advisor thinks you need. Then find out what you need from each other to craft a plan to get you into the faculty position that you want. Within that conversation you need to ask your supervisor how an RAP helps achieve your goal; no more assumptions about YOUR life.
Just remember, your difficulties in publishing are also going to be a factor in your ability to get an RO1 as well. Writing a major research grant will take a significant amount of time and a lot of informal institutional support to get it right. Even so, if you think you can handle rejection (what 6% of new R01's get funded on the first try???), over the course of many years, that's fine... but are you entrepreneureal enough to run your own lab?
With your PI insisting that you remain a postdoc to help your status in getting grants, that's not going to be true after you have already attained a K award. You'd be taking a step backward. The expectation once you complete your K is that you should be ready to send in an R as an independent investigator (anyone from NIH could please correct me).
Talk to the person in charge of your K award or at least another academic faculty member/administrator who deals with grant administration. You need to really know your options in grant-writing given each choice, but you also really need to know what you have to do when your K runs out.
Again, my own belief is that getting those first-authors out is going to be crucial, but you cannot overcome the fallow period without first-authors very easily. You should be prepared to explain that (which may be a bit easier depending on what you had to do post-MD). While you need to start getting consistent publications, you also have to develop the personal strength to survive an arduous faculty search. What will make you stand out among 500 CV's from which at most 5 interviews are picked (over the course of 4-6 months including negotiation)? What type of start-up funds will you need to get off the ground? What type of environment would you like to work in?