Once you've unlocked the ability to do something (craft, purify, etc.), it will be available as soon as you get to Dragon Mountain in subsequent playthroughs (NG+) with the same save.

My impression after finishing the game is that everything tied to the anvil - embedding, purifying, crafting gems and "infusing" weapons - almost only makes sense to use in a New Game+ after you've already finished the game at least once. Without farming for gold or orbs I never had enough of them to do anything meaningful.

So, my tip for anyone who wants to normally play through the game without grinding more than the game already demands: Just don't bother with any of it. It isn't necessary to finish the game at all.

Exactly. The whole crafting system feels arbitrary and overblown, but still keeps me going since the game itself is great and that's where you can still upgrade something after you have almost all weapons...

The orbs required are ridiculously high and require a tremendous amount of grinding even play at level 75 difficulty 4. You get 27 orbs for redoing the trials and similar amounts for missions some even giving 52 orbs. Still, when you need orbs over a thousand to get anything done, it is a bunch of grinding. Puts doing the whole thing out of reasonable reach.

On my first playthroughs right now, I don't really see myself upgrading any weapons beyond 1 or at VERY most 2 ranks. Weird thing is, where I'm at right now (looking for the girls' daddy), Insane 1 is rather easy, but Insane 2 eats me for breakfast. Maybe I'm doing something wrong - I'm meleeing enemies 99% of the time, only switching to a bow/gauss to do sniping, and occasionally a rocket launcher for initial blast (or to try to get the second chance). Also been wearing the "-100% healing power cost" amulet ever since I found it early on and don't see myself taking it off (it's probably the reason Insane 1 is easy.)