Having Loki as a patron isn't very uncommon with Neopagans. He is a god that's very popular in the Eddas and some people identify with his perceived "rebel" nature.

But from a Heathen point of view, Loki is outlawed. In the Lokasenna he shows his true colors, by insulting the gods and he is bound for the death of Baldr. In Old Norse society, outlawry was a death sentence, it meant that the person had no support from their kin, and could be killed without retribution. So the outlawry of Loki would mean he is antithetical to the gods, and by extension mankind who rely on the gods for luck and preservation.

But... if you are not a Heathen, you'll probably have a different understanding of him. And thus, might not perceive him as being so malignant and destructive.

Personally, I would be suspicious if Loki claimed to be my "patron" or anything else. I would think that it's probably some trick of his. And that any kind of positiveness that comes out of it, is the wining and dining before the date-rape But I may feel that way because my attitude towards Loki is colored by the Heathen worldview, rather than a general Neopagan one.

So, take what you wish. ;)