Hi burgerdave and welcome to PF!
The notion of black holes as bridges to other universes is quite old and mathematically well founded. In the mathematical solution for a black hole, it is quite simple to use a set of coordinates which shows two asymptotically flat universes with a black hole between them. In this simple situation, nothing can pass through the hole to the other side, however. Unfortunately, popular science and science fiction seems to have ran with this concept a lot more than is necessary. The concept of a white hole, which is a product of this same coordinate choice, also seems to garner a lot of attention. Unfortunately, the truth of these objects is that they're entirely mathematical. They exist in a universe that has been around forever containing only the black hole which has been around forever. This simply is not our universe.
At this point I'd like to point out that personal theories are against the forum rules here. It's our goal to try and educate people as to the current state of science and, when appropriate, where current research and the cutting edge is.
With that in mind, in case you were wondering why your musings do not make any sense, there are several reasons. For one, stars simply are not born in this manner. Stars are born when a cloud of interstellar gas collapses in on itself enough to begin nuclear fusion -- they do not mysteriously pop in from the vacuum. Also if you're interested in black holes and other strange astrophysical phenomenon, I would advise you to drop your egregious use of analogies. The world simply does not behave as common sense would dictate, so trying to equate matter to water and black holes to valves is going to lead to more confusion than anything else.
(Note: We do use analogies to explain some mathematical concepts, for example the balloon analogy of the universe or the bowling ball on a rubber sheet model of general relativity. While these are helpful learning tools, I always stress that they are nothing more than analogies -- not the theory itself! It's always good to keep that in mind)
If you have any other questions regarding this I'd be happy to try to answer, but just remember the 2nd paragraph.
Cheers