There's really nothing wrong with Anime. Most of those references to demons are either mistranslated (as has been said earlier). Those that weren't, sometimes head towards the original meaning for demon. The Greek word daemon just means "spirit" and has been used (even in the writtings of Paul) to mean what we translate as angel. Angel means "messenger", so demon would actually be a better description of heavenly beings that we call angels who don't deliever (say, guardian angels). As for symbols, it's probably Shinto or Buddhist (neither of which is demonic, except Shinto if you go with the original sense of the word demon). Aside from that, I initially was worried about things like pentagrams, but then I made it a point to find out a symbol's meanings before I pass judgement on it. For example, the pentagram was used by medieval Christians to represent the five wounds of Christ. Wiccan's use it to represent the four elements and spirit (which would be applicable for any religion that believes in a Creator). The relation with the pentagram and Satanism was actually made up about one hundred years ago by some people that didn't know what they were talking about. Try finding out what symbols mean (don't go with just the anime, either).