A lot of Eclectics work with different Deities from different pantheons. Some would consider themselves Omnitheists. All of the religions you mentioned are polytheistic and at least the first two are hard polytheistic. I think the most important thing is to make sure to research into the Gods you work with. Not simply the surface archetype regurgitated stuff but really read into their stories to get an understanding of them to respect them properly.
Re: Different paths into 1 By: MagicShawn / Novice
Post # 4 Apr 01, 2018
It is wholly possible, although I would recommend sticking with one tradition or pantheon during a magical work. I wouldn't mix them into the same working, but you can use whatever traditions you want. Also, I would recommend reading The Ethical Eclectic by Kaatryn MacMorgan-Douglas. You can get it from Amazon for under $5.
I would say you can interact with all of them, but you probably want to keep them separated. The rules for Hellenic worship, Nordic worship, and Kemetic worship are very different and if you mix things you are walking a fine line of not angering the Gods.