Yes, these theories can pretty much be put in the same framework. You’ve indicated that you’ve read stuff like Seth and Cayce, but have you ever spent time with A Course in Miracles? I think A Course in Miracles manages to reconcile this issue. The view of the universe and existence I give on my own website, which is similar to A Course in Miracles, also reconciles this issue—so
check it out. Basically, if you start from the subjective reality perspective and consider that there is really only one of us, then all other people and things are essentially reincarnations of your self. The classic idea of reincarnation just happens to attempt to trace in a linear way one incarnation to another. But in the grand scheme of things, everyone is a reincarnation of you (including me)--it’s just that it is nonlinear. We are dreaming up this universe because we are entertaining the idea of non-oneness or duality. Lost in the idea of dualism, we pretend that we are individuals separate from God/oneness and separate from our fellow selves that we make other and outer. And so, as long as we remain dualists and pretend we are special individuals we will reincarnate due to our karma. Karma is simply like a measure of the level of vehemence we put into maintaining our sense of individuality and separation. Anyway, explore my site and you’ll be able to see what I’m getting at here--this is actually something I’ll probably write an entire article on eventually so thanks for bringing up this question. All this stuff makes sense when you work from a coherent ground. And when you can make sense of it all, you’ll know you’ve found a coherent ground.