because I am based in a city that does not specialise in my chosen career. How is this fair?
I would expect your ex to argue that this was a choice you made freely. Also, the court won’t care about what’s fair for you, only what is right for your daughter.
Some of you seem to imply I have to choose between a decent job/returning to my career/earning enough money to live on or leaving my DD with her father. Also, how is this fair?
I can see how it feels unfair and it is a choice you will be left with if your ex doesn’t agree and the court doesn’t agree you can take your daughter.
It's not ok for my ex to suffer seeing less of DD
This is the wrong way round. It’s not about you or your ex suffering, it’s about your daughter’s relationship with her father significantly changing because you want to move. Also her friends, her school etc. If this ends up in court, you must keep child focused.
I did not say at any point that you are acting unilaterally, btw. You did ask what would happen if you just moved without his permission. That would be acting unilaterally.
It’s not reasonable to suggest he moves with you. I wouldn’t recommend bringing that idea up in court.
FWIW, I’m in a similar situation to you albeit many further years down the line. I get the frustration of being held back because of a decision made many years ago. I simply value my children’s 50/50 arrangement to move any significant distance away.
If you’re only going to be working part time, could it be argued that isn’t going to allow you to advance very far in any career?