If you don't, your rabbit will continue being aggressive. She will probably become territorial too (which can eventually lead to spraying pee on the walls and pretty much everywhere... believe me it's awful) and there will be a point in time when the spaying won't have as much effect on her personality because she will have behaved that way too long. As an added bonus, your bunny risks false pregnancies, which will make her stressed out, can give her mastitis and serious health problem. In the end, your bunny will probably have ovarian cancer, which generally develop after 2 or 3 years and will kill your bunny around 4.
Spaying will reduce the digging, the aggression, the health problems and give you a (mostly) clean rabbit. There is nothing to do against chewing though. You have to protect the things she chews and give her safe things to chew, like apple or hazelnut tree branches, cardboard boxes... and be patient. It will lessen as your rabbit gets older. My girl is 5 and a half and it's been a long time since she's last done something naughty. Tybalt was a nightmare during the first year and he's steadily getting better (neutering did him lots of good, because he was the worst adolescent bunny I ever had, destroying and peeing EVERYWHERE, waking me up every night by jumping on the furniture, ate tons of my books... he was a nightmare).