So this response is written bearing in mind that I'm still learning and building my own path (and so I sympathise with the search for a language to express this stuff, because I'm still seeking). Oh, it should perhaps also be noted that I only skimmed the main article you linked (and that I sort of have difficulties with comprehending these sorts of writings).
I too have both my doubts and my beliefs, and would say that while my 'outline' beliefs have been pretty much the same (therefore fairly fixed) since I first conceived of them, my whole outlook has something of a... not 'fluid', exactly, but a sort of... "non-rigid-ness" to them.
This is also all rather difficult for me to articulate (for some reason), so please bear with me.
In brief, I believe that there's some sort of a universal life force energy which is the nearest thing I have to a deity, which is worthy of reverence (I don't really have a name for this, though I'm aware that some names exist for the same or very similar concepts -- chi, prana (The Force, if you're a Jedi!)).
Hand in hand with this I believe that our natural world is worthy of preservation, and of reverence too. This I conceived of in, I think, my very early teens or possibly at an even younger age and therefore, since it's something that has spoken to me on a deep level for all those years I tend not to question it, and consider it to be my core belief.
Since I believe we're all beings of this energy I therefore believe in some sort of reincarnation, though exactly how this works I don't fully know -- I'm a believer in some things paranormal, and therefore believe it's possible, though perhaps unusual, for someone's spirit energy to retain a cohesiveness following their death.
I feel that sometimes this may only be part of their energy that remains partially cohesive (if that's semantically possible?). Other times, though I suspect rarely, it may be all or almost all of the person's original energy.
This is where, I believe, we get past life memories from, and how it's possible, though not necessarily altogether common, for ancestors to become spirit guides, for hauntings to take place, and so on.
There are aspects of this that I struggle with, though -- mainly the fact that if when we die our energy returns to this main 'pool' of energy, then this means that that pool is made up at least in part of persons like serial killers who've since had the death penalty or otherwise died.
Now, concepts such as good vs evil don't strictly fit into my belief system as expressed above, but I do consider myself a moral person, and the thought that my next incarnation could have part serial-killer energy is not a comfortable one.
I guess I just have to reconcile this by accepting that the energy is actually entirely neutral, and it's what's done with it by an individual in a given lifetime that is either good or evil.
Anyway, like yourself, outside of this context I do actually feel that I tend towards being a skeptic, too (well, certainly a cynic, but a good helping of skepticism too for the most part). But I instinctively feel that there's a realm or a layer or a supernatural 'over-lay', or some other terminology I can't quite name for a thing which I can't quite articulate... something which is set outside day-to-day experience and which we can only understand on a spiritual level, not a scientific quantifiable one, not as things stand.
Do I choose beliefs for pragmatic reasons? In a sense, yes, because that core belief I mentioned is the belief that simply came to me and felt the truest to me, at an early age and ever since -- although you might also argue that, since it's sort of instinctual, then can it in fact be described as pragmatic?
Is this based on what works? It works for me as things stand, yes -- again because it feels truest. However, I should say that in terms of practices I'm still very inexperienced. For example, when it comes to working with energy, even things like meditation -- I'm very much still learning.
Do I shift between beliefs in different contexts? I'm not sure. As I said above, I hold a kind of a core belief which doesn't really change, but I am trying to remain open to new possibilities.
For example, I don't really have a pantheon or any deities in my belief system at present but I feel the notion of archetypes is definitely a valid one.
Are my beliefs metaphorical? Well some of them, perhaps. Not so much that core belief which I set out above, but the fact that I ascribe a certain level of consciousness to the life force energy (call this Mother Nature, or whatever you will) -- perhaps this is metaphorical, for all I know, as I've yet to establish any form of identifiable connection with this consciousness or entity.
And as for a theory to reconcile tensions in my beliefs -- I wish I did! But again, this is still a work in progress.