Do you think by obsession about the paranormal could open yourself up to be targeted by spirits/demons?

The answer to your question is no. Just being interested in the paranormal will not cause demons or negative spirits to bother you, that is just a myth. I have used Ouija Boards and Tarot cards and many such things and never had any entities bother me. I grew up in Pentecostal and Baptist churches and was told many things like this but I found them to just be stories.