That's why it isn't science ;)

Maybe when QM was being developed "collapse" was a debated concept; I'm not too familiar with its history. Currently though, modern QM predicts that ensembles of identically prepared systems select an eigenstate of the linear operator corresponding to whatever observable it is you're measuring. Each of these eigenstates has a probability that can be calculated for it, and the mean value of these measurements is given by <Ψ|A|Ψ>, where A is the operator. I see no implications of collapse with this -- just probabilities of what values you will obtain in experiment.

Not exactly, your statement is correct for single states, however it breaks down for entangled states. When one wavefunction describes two or more particle a measurement on one particle can be thought of collapsing the two particle wavefunction, which then forces the other particle into a well defined state.

Edit, I am not arguing in favour many worlds theory, only that the 'collapse' of the wavefunction is a well developed and useful idea in quantum physics.

Quantum entanglement doesn't seem to be particularly unusual any more so than the fact that electron-electron correlation must be taken into effect when computing energy levels with some kind of QMC. All particles within a quantum system are correlated, so entanglement just kind of falls naturally out of that; I'm not assuming any kind of locality. I suppose what you're saying is that collapse is defined as the process of "fixing" these correlations?

  >  I've never understood the weird fascination with "many-worlds".

Thinking about the "what if" constitutes a deeply human tendency (or weakness, if you will). The notion that all our missed chances, fantasies, dreams, ideas, etc. may be actual as opposed to potential -- that's way too attractive a thought to ignore.

This theory does not claim to be Science as it uses a different model to find answers.

Science is about explaining the world/universe, not merely making predictions.

This came up at Galileo's trial. The Church was happy to accept his theories as mere predictions of astronomical observations. What they wouldn't accept was that the earth actually DID move around the sun. But Galileo was adamant on explaining what as actually out there. "According to popular legend, after recanting his theory that the Earth moved around the Sun, Galileo allegedly muttered the rebellious phrase And yet it moves." (http://en.wikipedia.org/wiki/And_yet_it_moves‎)