Seil

As a rule of thumb, work metal just after it's cooled to a non liquid state. You could look up the appropriate temperatures for the specific metal, but the aforementioned method is always going to work and it'll be in the appropriate range for welding as well.

The only thing you can't heat in the forge is ores. You can use the forge for food, melting ingots, heating unshaped metal, molds, etc. The temperature and ability to have five items going at once makes cooking fast and easier to manage. Usually when I make metal, I do it in batches and mix the alloys etc and store the liquid metal, or store it at a workable temperature(at least right now, I'm only a couple tiers in). So I use the forge more often for non metal related things. I also prefer stone bricks etc to wood for building, and start on charcoal production, bloomeries and a forge before establishing a base =p I just sleep through the night haha.

I've only recently started playing TFC, and really one of my biggest gripes is the immense number of useless materials. It's great to have so many things that can be given a use in the future, but on the other hand it's annoying having a lot of stuff that literally just takes up space. Generally in games, coming across a new material is reason to rejoice - even if it's something you need to progress further to make use of, there is a reason to be happy you found it. In TFC, there are times where I've found myself feeling disappointed because I found a vein of, for instance, olivine. Now I have very large vein of olivine pinging my pro pick, making it more difficult to pinpoint something else I've noticed nearby. In the end, I get a full chest or more of an entirely pointless material and a feeling of frustration. And then there's the chests upon chests of gems x.x On the upgraded firepit note, isn't that essentially what the Forge is? Sure, it burns coal/charcoal instead of wood like your example, and can heat metal(but not melt ore), but it's still an upgrade to the firepit. Upon getting a forge and having decent charcoal production, I use it for cooking as well as re-heating metal etc. The extra slots take away much of the tedium of using a number of firepits for cooking. And at that point, due to bloomeries etc, I would rather be using most of my wood supply for charcoal production anyway.