From the responses, I'd say that 1) is the best bet for an acceptance. The fact that the dean has written to the adcomm recommending your acceptance is very positive. I guess the only things that could keep you out is if they don't have funding for you or if there are better fits, but I'd imagine that the Dean's recommendation would carry a lot of weight.
2) sounds slightly better than a generic response. Yes the POI sees a fit for you, which is good, but it's also possible that they see a fit for 100 other applicants.
3) sounds promising and hopefully the POI will follow through in speaking with members of the adcomm. If so, then that would help, but it would depend on whether you'd be among the best fits of the applicants they have.
So if I were to rank your responses, it would be 1 > 3 > 2, although it could be that 1 > 2 > 3 depending on how much of a fit the POI in 2) sees you as.
Good luck!