Welcome to Thunders iwanbsc, you have a great starting size that many around here envy and want, if you are determined and persitent enough all the information to reach your goals of 9x7 is here. Remember to make heavy use of the search feature here at Thunder’s when craving new information and techniques and learn how the advanced search feature works to take the best advantage of it. I can’t tell you how many times it has helped me out before. :)
I don’t think foreskin restoration should effect length or girth gains. But go for length first before girth to make it easier and quicker gains for yourself in the long run. I won’t explain the reasoning behind this right now cause I’ve already have many times lately just look around here and read.
You have a interesting question about the hot wrap. I don’t exactly know what the perfect way to warm up your dick is for quickest gains but I would say I have tried three different ways of warming up using a rick sock, hot wrap and soaking my dick in a glass of water for 5 mins and I prefer the microwave heated rice sock the best for warming up when I do warm up. You could also just stand in a shower with really hot water for a while until your dick was nice and warmed up. Also let me clearify for you that when I say warming up I mean my dick is more pliable and stretchable, it feels more jelly like and squishy then if I had not warmed up. Also know that there have been many great gainers here who have not used any form of warming up before doing hanging, manual stretching, girth excersizes, etc.
It’s all in the end up to you, learn the sensations and subtle feelings that your penis and body tells you and over time you will gain some skill in learning when you are probaly wamred up and not and what a good stretch feels like and what a good jelq stroke feels like etc… Just keep practicing new things and keep at them. Good luck…