The rewards for the final lords crucible are - 1st 1000 of each plucked eyeballs pilfered coins and severed hands - 2nd 150 umbral scourings - 3rd the Dusk tincture.
you're in luck I actually did a video breaking down my stats, gears and build some time ago. here's the link ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-M1BWrXqbCBg.html
Not sure if I'm much help with crashes. but personally my client rarely crashes so it maybe a problem with your PC ? does it always crash at the same point in the game?