Streetwind

Pretty sure there is no random spawning mechanic either. I've played for multiple ingame years in worlds with zero wild crop respawns.
You just sometimes come across a plant you missed the first five times going through that area. It happens. Just like it does with surface copper deposits - where you return from your three thousand block copper scouting mission only to discover the deposit right next to your base that you completely missed all this time.

Not a bug, working as intended. Every item maintains its heat for roughly one minute after the last time its temperature increased, provided that nothing else updates the item's temperature in the meantime. Not just in the firepit, but with all heat sources. This is supposedly so that you can do something with the item you just heated before it cools down again, for example smithing a tool on the anvil.
Updating the item's temperature through any means waives this grace period immediately. For example, you can heat a stack of 30 unfired bricks to 600°C, and then pull it out of the fire. It will maintain those 600°C for about one minute. But as soon as you merge one other brick into that stack, the stack's temperature will be recalculated to be the average temperatue of all 31 bricks in the stack. This modifies the temperature, and so the grace period is waved, and the whole stack starts cooling down immediately.
You can actually use this behavior to exploit the heck out of the firepit. For this reason, the roadmap already has a rework of the firepit earmarked. And who knows, maybe the temperature system as a whole will get overhauled at the same time? Or not. We don't know. Nor do we know when it will happen.
Until then, however, this is not a bug.

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You can save the ruined bloom until you have a windmill set up that drives a helvehammer. The hammer can work blooms for you, so you don't have to do it all yourself. And it will produce a perfect ingot every time, even when the original bloom would not have enough voxels for it. So it will actually repair a bloom that you accidentally ruined.
It will also produces plates from ingots, and plates can be used to start chainmail recipes, so the helvehammer is a great help when producing heavy armor. Every workshop should aspire to have one!

You're supposed to be able to turn the ingot into chunks with a chisel... I believe by crafting them together.
 

When you take the crucible out of the firepit before the contents melt, the contents will spill out onto the floor. Depending on how your firepit is built/situated, you may not see this.
Just like all other items, if these bits are not picked up within 10 minutes, they will despawn.