Can I still be a Heathen if I have a ambigram …

Can I still be a Heathen if I have a ambigram “ANGEL/DEVIL” tattoo and have a tattoo of a sigil that one of my Wiccan friends created for pain relief? Also do you know any prayers for stuff like thanking for meals, thanks for waking up and for protect before I travel?

Yup! 🙂 The tattoo’s aren’t an issue, and for Norse paganism there’s no problem with incorporating other deities into your worship – the pantheon isn’t really considered finite.
There is a point where I wouldn’t necessarily consider a person’s practice to be “Heathenry” or “Norse paganism” although defining that line is not something I have any interest in doing.
Generally though, I would say there’s no objective problem with a Norse pagan making use of a Wiccan-sourced sigil (especially as sigils are just a common facet of witchcraft which, itself, has no inherent religious affiliation)

And yes 🙂 I’ve written a few pieces that fit with what you’re asking

And I’m working on a few different pieces at the moment, one of which is a morning-prayer, so keep an eye out for that