While crafting a furnace entire lighter fuel gets consumed
While crafting clay mold of an ingot, ingot gets consumed
So on
Is this the intended way of it to work?
It is the only way it can actually work, there is no other way of making it work in the crafting table properly. So use Bricks instead of Ingots for Ingot Molds. Same for using other things to light the Furnace.
How does crafting with a bucket of liquid return the empty bucket? Can’t it work that way?
Container Items, thing is they can only be used for one thing, so emptying the Lighter 100% would be one purpose of the Container Item, same for damaging Tools when using them in crafting. This does not work with certain types of Items that need container Items for filling them with Liquid for example, such as the Lighter.
But tools don’t get used completely; they just take a little damage. So why can’t the lighter just take a little damage?
Because unlike Tools, the Lighter is a Fluid Container, meaning emptying it equals draining all liquid from it. It is literally ONE function that does BOTH the crafting and the fluid draining from the thing. Yes I know it is bullshit, but blame Mojang or Forge for that one.
Could always make a new machine to use instead of vanilla recipes, then you could return or just not use things properly.