Hi Sarah.
Regarding the stay in Korea - you can buy a rechargeable subway card. It is about $3-$5 i believe which is not refundable but then you can put money on that card and just go through the subway gates and put the card on a reader and it will substract a reduced fare compared to the single tickets. You can also use that card for other transportation, like bus and taxi and I believe some shops also accept it.
The hotels near the clinic are rather expensive as it is in Gangnam. Since you will only be in the clinic 3 times, I am not sure if it is worth it. I would also not hibernate all that time - Seoul is way too interesting and honestly after a day or two you dont feel at all like you had surgery and would just get bored in the hotel. Phil House is about 30 minutes away from the clinic - by taxi or subway. I found this quite bearable, but getting to the interesting parts of the city took also that long, so that made it a bit of a less favourite location. It basically also only pays off if you are travelling with a friend since the rooms then dont cost more for 2 people as for 1 person. The breakfast is super simple though, but you have a fridge and washing machine and even a kitchen, so you can basically cook and prepare food yourself. We used the breakfast twice and the rest of the time had bread and stuff in the fridge for breakfast. Mainly because we tended to sleep until 10am

- Its not a comfortable room to stay all day long though, but they have a common lounge area and a rooftop terrace where they also offer BBQ.
Regarding your trained voice and your expectations - what expectations do you have - how is your trained voice like - is it much higher in pitch than your untrained voice? Is it in the normal female range? Do you feel it should be higher in pitch?
Part of the result seems to be that the sound of the voice changes (less undertones), it is easier to reach higher pitches and for example laughing changed for me. Another effect is that it is becoming natural to use the voice that before the surgery was the trained voice or elevated pitch voice. You certainly can increase this even more with using some of your voice training. I could probably with ease speak at a 240 Hz voice now if I really wanted to, but it would mean to elevate my voice again, so I don't.
I think you can discuss your expectations with Dr Kim. They will do the voice analysis first, determine your untrained pitch and your trained pitch (maybe try out your untrained pitch before the examination, so you are able to do it. For me it was really hard to do because I have not used that for 17 years really, except some few occasions pre op to measure my pitch in PRAAT) - the goal of Dr Kim then is to go up from your original pitch to above 200 Hz - if that is done with the 75 Hz he usually aims for, its ok. The length of the suture can be varied and I think he has some parameters that influence that. In my case for example it seems that because of the asymmetry of my vocal folds he had to use a bit more length and shortened it by something halfway between 1/3 and 1/2, probably around 40%. He will usually not really be in favour of pushing a voice way above the 200 Hz level, as this may be unnatural then.
If you can post your voice parameters, we can discuss them