They will not pee everywhere if they are neutered, but females are also not territorial if spayed. Friendliness is a rabbit-by-rabbit trait, each one is different.
The book is wrong. You should not house rabbits with guinea pigs as it is dangerous to the guinea pigs. Two male rabbits are the hardest to bond. It would be wiser to adopt an already bonded pair of adult, fixed rabbits.
We are as gods to the beasts of the fields. We order the time o' their birth and the time o' their death. Between times, we ha' a duty. - Terry Pratchett.
"Men have forgotten this truth", said the fox, "But you must not forget it. You become responsible, forever, for what you have tamed. - Antoine de Saint-Exupéry