Answer:
Yes it is (we already have one)
An international orbiting space station would be a great idea! We could use the space station as a refueling point for passing spaceships. This could helps us achieve things such as space exploration, mars/moon colony, or even contact with other unearthly organisms. This could also allow us to conduct space research.
No it isn't
An international orbiting space station is a horrible idea! The first thing to think about is the money. This would put the entire area in stasis as we try to raise money for the space station. We also need contact with the humans/robots in space! Building a space station would confuse other nations as to what we plan to do with said space station. This could cause a war of some sort.
That is true, you limit on what you can do with them.
There is no defined limit on the capacity of the brain. The brain's capacity cannot be measured as it is not subject to a defined "space" where the memory is kept, and it is not such that each neuron is responsible for a single memory. The brain has complex mechanisms of memory storage, that even improve if trained.
An example i can think of is...
the amount of salt present in human cells cytoplasm suggests we evolved from species in the sea
