For the nut work - please do comment - I’m willing to listen to anything feedback. That’s the only way to improve.
No worries. I've done a fair amount of nut work over the last 5 years and I'm still improving my methods and learning better ways of doing this & that.

I agree that it’s way off perfect and do plan to refine it or even replace it - probably at the next string change.
You probably needn't replace it. The slots look good and there's plenty of material there to work with. Nothing there that can't be fixed as far as I can see. It's hard to tell 100% from the photo angle, but the string action looks acceptable (maybe a little high?) better to need to go down than up!
With fine tuning the slots, I will just do one stroke of the file; put the string back; check the height; repeat. It can be tedious, but better than sawing away with the file only to find you've gone too far!