A definite must have to keep just in case when you need it!! I would mostly use it to prevent infection when I get wound/scratch/insect bites etc. and also for other skin problems. Just put a few drops in some water and either soak the affected area in it, or dab some on using a clothing or a cotton ball/pad. It has a great smell and has never reacted with my sensitive skin.
I also use it to get sticky bits off objects. Just rub some on the object using a cotton pad and the sticky bit is off in seconds!!
A bottle doesn't cost a lot and will go a long way
I haven't used it for many other things on the list but I always have it on hand. I always have the kids shampoo and conditioner in pump bottles to make it easier for them and I always put tea tree oil in their condition to help keep nits at bay ... Sure does the trick :)