: ...Socialism/Communism is predicated upon the wealth created by Capitalism. To me (please correct me if I am wrong) this implies that socialism is an innefficient system (i.e. it has to have a helping hand from the wealth of capitalism) and is therefore not productive.
This is a distorted, quickie version of dialectics.
Socialism can only emerge from capitalism when the internal logic of capitalist production breaks down in crisis of overproduction, immiseration of the (largely neo-colonial) masses, and imperialist struggle to redistribute spheres of exploitation (in the neo-colonies).
These are the negating features of capitalism---which accompany the high level of productivity socialism is predicated upon.
Capitalism, BTW, did not invent high productivity (apologies to Ayn Rand occultists).
Scientific development was a predicate of capitalism but it is not capitalism itself.* Capitalism is not so much the mode of production (that, admittedly, characterizes capitalism because capitalists monopolize it) but, rather, capitalism is the social relations that (only) accompany the mode of production.
: Without the wealth to "liberate" from the bourgeois, socialism would go belly up in a short period of time as it's citizens go hungry and die in the "workers paradise."
Socialism only liberates what the workers made (and make) in the first place---the crops, physical plant, raw materials, etc. These are all things made by the labor of 'common' proletarians, past and present.
The primary reason that socialism has failed thus far is it has been established in semi-feudal (i.e. PRE-capitalist) economies unable to provide adequately for all .
Interestingly enough, as I pointed out here, the former Soviet Union NOW has the level of technological maturity to actually sustain socialism (not to mention the incentive)...
: Even if the revolutionaries timed everything just right so that they insurrected the capitalist government and instituted their own socialist/communist one, things would eventually fall apart.
Easy there with those flying premises! Capitalism took CENTURIES to dominate the world. For hundreds of years, monarchist landholders (represented ably by Carlyle) scoffed at the idea of the 'mere' clerks and merchants taking over and running the show...
: Quite simply, to maintain and augment prosperity, there must be constant development.
: Constant development which socialism/communism cannot and has not provided.
Again, another quick assumption.
You're right: communism / socialism has not provided (for the reason stated above) constant development in the past. That's not to say it won't---in the proper dialectical context---in the future. There is no end to history.
* To cite but one example, Einstein's theories have been used many time by capitalists, but the man was a socialist. (See Monthly Review, first issue, May 1949.)