With 1750 grafts, getting that perfect density won't be possible, but letting your hair grow longer can help cover up any thin spots, and you can always use hair fibers to fill in any gaps and make it look denser.
When it comes to the crown, it's tempting to go all-in for density, but it might be smarter to hold onto some grafts for the future, especially since you've got a good amount of native hair in front and you seems to be young and may loose some native hairs in future.
As for the hairline, i would say, a "V" shape might be worth considering over a "U" shape. A "V" shape tends to look more natural and can help hide any signs of a transplant better. Plus, it can age well and save you some grafts down the line. But hey, at the end of the day, it's your call. You're the one who's gotta look in the mirror every morning!
I hope this helps you. Best of luck.