On the other hand I read at bitcointalk that if you use the same wallet on 5 computers it basically combines hash power into one similar to how a pool functions.
Don't clone your wallet!! Cloning your wallet to do anything besides backing it up is a bad idea.
It might work perfectly for a while... but you are very likely to get weird behavior from bitcoin sooner or later, because doing that is not tested or supported.
Where 'weird behavior' is one clone of the wallet shows one balance, the other clone shows another, and you might end up with coins that you can spend from one wallet but not the other (or, worst case, end up with coins that neither wallet is able to spend).