This is legal language, which many people think means “obscure” but really means “precise.” Just looking at the first three words, there is a vast difference between “without limiting” and “without otherwise limiting.” The agreement/contract/clause clearly does allow “limiting” of whatever or whomever, but only to the extent described in the contract and not “otherwise.” Lacking the word “otherwise,” the meaning of the sentence would be that it voids the prior provision.
Let’s try an example. I sign a contract with you allowing you to come into my back yard and pick apples from one of my trees, but I am limiting you to that one tree; you can’t pick my apricots, nectarines, etc. I want to make sure you know that. So I put a clause into our agreement that says that you cannot disturb my trees–but that’s contradictory, because I am saying you can disturb that one tree. So I insert the word “otherwise”–as in, “you cannot otherwise disturb the trees in my backyard”–to underscore the fact that you can’t pick any of my other fruit, but not voiding the entire contract by saying you can’t disturb my trees at all, which is the way the clause would read if I didn’t include “otherwise.”
To many people, this sort of thing seems very anal and picky, but I assure you that literally billions of dollars have been lost by people who didn’t make their contract language very precise.
Edit: If you want a philosophy text that’s written in plain language, try John Locke or David Hume. (Their English is naturally old-fashioned but their arguments are very clear.)