You're not bothering me at all
Perfumes can have bad reactions for certain people, so if anyone is sensitive, be careful with what you use. Essential oils are usually fine, as they are simply extracted from plants, but I have heard of people who had sensitivities to them.
For using essential oils, I usually just inhale from the bottle for some breaths, usually 4 or 5. This is recommended in aromatherapy too. You can diffuse it any method, such as heated stones or a diffuser as you mentioned, or the sticks that go in a jar.
Go with what you like, if you don't like the scent of something then don't use it. I don't know enough to say if there are any that should be avoided, just make sure they are decent quality though.