DD is 9. EPCOT has been her absolute favorite park other than MK since she was 2. We also go to DL, and EPCOT is the only thing she misses when were are there. EPCOT actually has a ton of princesses, Snow White, Belle (blue dress), Sleeping Beauty, Jasmine (often with Aladdin), Mulan (while technically not a Princess- merchandising typically groups her with them). Mary Poppins and Alice are also there. Does she like Phineas and Ferb at all? They are big with that age group here, and DD is absolutely nuts about the Agent P missions in World Showcase. That is one of her favorite WDW things- the special effects are really cute. DH loves them too- more than once I have had to pry the communicator out of his hands, and make him give it back to DD. Biergarten is a favorite with both DD and DH. EPCOT is a 2 full day park for us. If you asked DD, she would say if you are going to skip anything- skip AK. She has never been a fan because there is no real princess presence there, and we have a good zoo at home, so she is not interested in going around and looking at the same kind of animals she can see at home when she could be doing "Disney" and princess stuff instead. I like AK, but DD is not a fan. She usually humors me for a while and then she is usually begging by noon to go back to EPCOT or MK. I will say that has changed a bit since they started doing the Wilderness Explorer Adventure Badge booklet- they can go around the park and do things in different areas to earn badge stickers. That kept her interested in AK until about mid-afternoon. It is still her least favorite park though. Does your 9 year old girl have a decent zoo at home? If so, she may tire of AK very quickly. Again- another aspect of going with a princess loving girl! Also, I don't know what the construction status is there currently, but last fall it was bad. The construction walls really detracted from the AK experience in my opinion. Someone else that has been there recently can probably tell you if it is better now.
As far as whether eliminating the park-hopper is a mistake-that can be remedied. You can add it on while there if it is needed. I don't know her energy level-but my 9 year old DD is an open to close parks girl. For us- we pretty much always go back to MK or EPCOT on AK day. Unless it is the holiday season with Osborne lights- DHS is another day where we often hop to MK or EPCOT in the evening (unless Fantasmic is important enough to you to face that Crowd- we prefer it at DL, so we skip it at WDW). You said you love evening EMH- we do too, but we don't like the extra crowds EMH bring during the day. We typically go to a different park, and then hop over for evening EMH in the evening. We like the flexibility park hopper provides, but there is no reason for you not to attempt to save the money on it-knowing that you can change your mind if you suddenly feel the need to hop!
As far as Anna and Elsa- you will need to get there VERY early and be in the front of the rope drop pack. In addition to competing with a lot of the rope drop crew, you are now competing with the crew who booked BOG breakfast specifically to be in that area and get to A&E BEFORE the rope drop crew gets there. If you aren't at the front of the rope drop pack-you can expect that line to already be 45 minutes to over an hour by the time you get there (7DMT can be the same way). Don't give up on the FP+ idea. If it didn't happen on your 60 days (looks like you are past that), then keep trying daily- several times a day if possible- things do pop up.
Just a warning- a PP talked about their DD not wanting to wait any significant amount of time for characters/signatures and preferring rides. My DD has always been the exact opposite. The most important thing to her is the characters. She would be happy spending an entire day going from one character to the next and not even riding the rides. In fact, we had one day (I think she was 6 or 7 at the time), where we did go from character to character all day and only rode 2 rides the whole day. DH and I were going nuts. She will still tell you that was the best day ever. (We went back the 2nd MK day and since she had seen everybody that day was about rides and everything else thank goodness). Don't know which way your 9 year old will go. Since she is nuts about the fact you met Anna and Elsa, you might find that she is a character hound like my DD.
I think it is wonderful that you are making her dream come true! Going with a girl is a ton of fun! Have a fabulous trip!