First off, if you allow your gifts to control you, you'll get no where and end up feeling like you are going crazy.
Voices- For this you can actually try and listen to what they have to say, I wouldn't try to speak with them until you are sure of their intent. Once you are sure they are of no threat you can explore further options such as communication. With this I would work slowly and take your time. Be sure you are understanding what they are needing/wanting and if you feel comfortable on acting on that I would do it.
Dreams- We all have the ability to control our dreams, but as the Elder said it could be that you are visiting the past/future and should proceed with caution. Changing destiny/fate can have alter the natural order of things and should not be taken lightly. 3 fold rules apply.
Demons- Should not be messed with. They are manipulative and malicious.
As with anything in life, you your gut feeling, listening to how your body and mind are reacting to a certain situation will almost always lead you in the right direction.
"When you think night and day and every moment only of pleasing me, things will be very easy for you."