As far as heating vs hammering goes, that all depends on what kind of heat and what kind of hammering. 10 minutes is a long time, but for charcoal, it isn't so outrageous as it would be for coal. In between forging, it probably takes 20 seconds for me to heat 5/8" round to a bright orange heat. I highly recommend using coal if you have acces to any. Charcoal is good for learning, and I've seen impressive things made in a charcoal fire, but if you try real coal, you will never go back. Look on Craigslist. Sometimes you can find it really cheap there. Even free. Just buy a little bit before you buy a whole truck load, so you can make sure it burns well.