Hi, can anyone tell me what the required Vacuum pressure is required for wet laying Carbon Fibre?

Theoretically this is 100% true. In most practical hobbyist applications vacuum is applied to keep the carbon cloth in the edges of the mould during cure and that's it. If if you apply 50% vacuum (wich I recommend) it will already remove almost all excess resin. The coth will be pressed together untill the vacuum force equals the force the cloth creates because of fibre stiffness (measure the cloth carefully with a caliper, then again, but press the caliper hard together. There will be a small difference). The resin itself can't create forces to withstand the vacuum while it's liquid, that is the physical definition of a liquid. 100% vacuum will only press the fibres a little bit more together, wich will result in a slightly higher fibre content.
There is nothing like sucking out to much resin. If there is already no pressure in the resin, there is no force wich will move the resin out of the laminate. What really happens is that you degas the resin inside your laminate if you apply too much vacuum. And since there is no movement in the resin, the air can't escape the laminate and will accumulate at the fibre crossings.
If you degas resin in a clear view chamber, you will see that almost nothing happens until you reach about 90% vacuum. But after that an air volume many times that of the resin will be released. Under vacuum pressure, but in case of vacuum bagging the resin will cure that way.