my feeling is that its only complicated before you understand it and then its pretty simple.
Oh, it's not complexity that worries me. The issue is alienness, the degree to which this all is disconnected from reality. Star Trek warp drive is "pretty simple", too, but that doesn't make it any more real.
I guess #1 is a good axiom in the sense that we have no reason to disbelieve in it yet, and it follows from a theory that is supported by observations.
Let's look at the others, then.
#2: The existence of "extrauniversal" realms is similarly accepted as part of seemingly consistent theories. However, from this does not follow that movement from "in" to "out" or vice versa should or would be possible, or does it?
#3: Gravitometric bubble does not sound like a property of our universe, so ending up in one would already call for the departure you postulate. While a number of the later axioms are relatively "easy" and typically only list fantastic possibilities, this one already seems to present a gigantic chasm for the required leap of faith.
#4: At least the rough properties of the gravitometric bubble would have to be known before its role in protection could be evaluated.
#5: I see no particular reason for this claim, since the whole idea is to operate the ship in a realm where gravitic interactions are different from those familiar to us. And in the very next step you in any case postulate that gravitic interactions can be affected by factors as such unrelated to gravity.
#6: Energy coming into phase with gravity is just gobbledigook. One would need to specify how the desired type of energy can interact with gravity.
#8: Interpreting the geometry of the interior of the wormhole as conventional 3D space within which travel through spatial dimensions takes place is a rather dubious move. But okay, this is what axioms should be about
: the defining of terms for later use.
#9: Same as above.
#10: This just piques my curiosity: why talk about "warps" when the idea is not to discuss the Star Trek FTL drive anyway?
#11: Okay, so this is just a list of means that might create a wormhole, according to various theories, and not actually a direct endorsement of those particular theories?
#12: Sounds like so much gobbledigook, applying potentially unrelated layman principles to phenomena not properly described.
#14: How do we leave the universe? So far, there's no indication that this would ever have happened to anybody or anything, only that our current thought constructs don't all categorically deny the possibility. One step to me sounds at least as difficult as the other - and we actually think we know how space rolls in the "natural" case, around mass, while we have no "natural case" to go by as regards the other issue.
#15: I see no evidence of the connection between hidden dimensions and the ability to control movement in or entry into a wormhole.
#16: Okay, the universe might be like that, and we might make use of it one day.
#17: Doesn't seem that anything in current science would predict this sort of an ability. It would require some very specific properties of the universe...
#18: Sounds nice. Here's hoping!
#19: A wild guess?
#20: A wilder guess? (Why gravitational energy?)