You have to be in Communion with the Catholic Church. You can't believe something other than what Catholics believe. I don't recieve Communion at other churches for the same reason. In the past I have been a soprano soloist at several Protestant churches, once I explained the situation no one seemed offended that I would abstain from recieving communion at their communion services. FWIW, Lutherans have the same restriction about recieving communion outside of their denomination. And, I suspect Episcopalians do as well.
Nope, at least not our local branch of the Anglican church. They give communion to anybody that steps forward. I attended a partner's funeral and some where offended that I didn't step forward to participate. Strange reaction. I occasionally abstain from communion if I don't honestly believe I am "in communion" that week with my church. I am a KC and ardent supporter, but know that I am not always in the place I should be spiritually to partake. I just stay in my pew and pray.
Oh well, guess I am just an old coot.