OK relax! Your in good hands! You've taken the first important step in finding a solution! "Out think your dog!"
Your observations of her behaviour sound spot on and very familiar! A harsh verbal "NO" can crush them! And yanking and cranking on them is also a "No" go!
The other dogs thing see here:
If you don't make other dogs an attraction from day one it goes along way to solving issues, they never happen! And see the Slip Lead Leash thread. a Slip Lead Leash is what I use. By and large when used properly it is not a yank and tool. Slip Lead Leash thread is in the first link
A Prong collar maybe to much for this dog and you. With a Slip Lead Leash you can "guide the dog" into the behaviour you want! It's about persuasion not force.
The Sit thing should be easy, you apply light pressure upward on the leash and press on the butt and say Sit. A light touch is your friend.
And these first "Sit on the Dog:"
Wheres my sanity: Sit on the Dog, aka: The long down
Energy - it's all about confid-tude
And the "Place Command:"
The Magic Of Duration Work | The Good Dog Life Blog
And some very good follow up on "The Place Command is here:
Read that then click on the thread for the Q&A I found another clip on Place that is very good. The whole thread is worth reading.
So go over that info regroup and do what Cesar says. "Take a deep breath and relax!"
Gunther Mastiff/Pit Mix 2000-2010
Heidi Brindel Boxer 2000-2000
Struddell White Boxer 2003-2013
Stewie Boxer/Pit Mix 2000-2001
Rocky BLK Over Size Wl GSD 2007-2017