How does wood compare to coal in terms of home heating efficiency

Currently there is no way to prevent people from doing this. The best way to ensure that it does get used for tools is to put your blacksmith right next to the stockpile nearest the mine, however its still not going to be that helpful.

You can also sell your excess firewood to a trader for coal, which should create a big enough surplus to let your toolsmiths work a while.

You only need 1 animal to breed them, technically. However, animals can die off for no particular reason, which means that you are best off buying at least 2 since the livestock trader is so rare that you don't want to risk having one die off immediately and having to wait for the next trader. Animal birth rates depend on if the pen is worked and how many animals are in the pen (more animals means more babies)