It sounds to me like the core of your argument goes something like this:
Religions disagree. However, reasonable people all tend to be in it in order to find some reasonable spiritual guidance, and those who share this goal tend to be able to have intelligent conversations together rather than blowing each other up.
Is that the gist? If not, sorry!
That makes sense. But I take issue with people who claim to belong to some group that has a doctrine--for example, that if your child disobeys you then you should stone him to death--and then put qualifiers on it, like "oh, well, that wasn't meant to be taken literally--it's just a metaphor." If a religion has a doctrine and you pick and choose and interpret and modify, then how are you a part of that religion?
What you're doing there is having a brain. You are a spiritual person seeking some sort of guidance, and you read widely and think for yourself. You've decided that some of Catholicism is good and some of Zoroastrianism is good and some of FSM is good, and you're constructing your own personal spirituality with your brain. It's not coming from a religion; it's coming from your own thoughts, and religions are nothing but sources of inspiration.
Why then do you call yourself Christian? You're not Christian if you disagree with chunks of Christian doctrine. Not that it's really possible to write down what most kinds of Christianity's doctrines are, although with Catholics you can always ask the Pope--that religion was clever enough to include an oracle.
Amongst people with brains, being able to say you believe something because it feels right, and maybe cite a few sources, is usually enough, but the fact that you're citing Christian sources doesn't make you Christian, does it? If you read the Qu'ran one night and suddenly start citing that instead but your beliefs haven't changed, are you now Muslim?
But is the core of their religion proving all the claims of historical continuity are correct, or is it in their relationship with nature and its feminine and masculine aspects?
Indeed. I've claimed above that being a part of a religion involves believing in and following its precepts. If one part of Wiccan doctrine is that their religion is old, then if you don't believe that, you are certainly less Wiccan. You may borrow from their doctrine in order to interpret your feelings, and you may order pizza with people who call themselves Wiccans--does that make you Wiccan?
Back to the real argument:
It's not like we're all in total lockstep, but then, neither is Science nor scientists, and that's a strength, not a weakness.
Completely different.
In the case of religion, we can all believe whatever we want (subject to the internal constraints of whatever brains we happen to have applied to the question, to whatever stuff society has taught us is right, etc...).
In sharp contrast, science is converging on the truth. It is absolutely provable that science is more correct now than it was at any (documented) time in the past. Why is this unquestionable? Because if you question it, then we can take some old science and some new science and make some measurements and see which predicts the data more accurately. Neat, huh? Try that with religion.
Saying that scientists are not in lockstep in the same way that religious thinkers are not in lockstep is disingenuous. In science, we're not in lockstep in the bleeding edge, and that's due to not having precise enough measurements, or powerful enough colliders, or the ability to gather enough data. Once enough quality data are available, we get into lockstep very quickly. For example, nobody believes that Newtonian gravitation is correct anymore, because we have very precise data showing that Einsteinian gravitation explains the data better, and we know our measurements are precise enough. There is no "I believe in Newtonian gravitation but we can still be friends"--it's simply known to be a coarser approximation than Einsteinian--let alone Aristotelian! Is global warming real? We don't have enough data to say for sure, but we are getting better and better data, and the predictions are becoming more and more clear--we are getting closer to lockstep, and that's a good thing. Same for cosmology, although nobody stands to make a lot of money if they can disprove that one, so we don't have massively publicised studies scientifically showing that the Big Bang is crap.
In religion, you can disagree with other religions because there is no way to reliably tell which is correct. In science, we constantly move towards a better understanding and we can prove it.
(Bitches.)