You didn't say how old the bunny is, but if you got him at a pet shop and have had him three months, I suspect that makes him about five or six months old. That's the beginning of the Terrible Bunny Teenage Months. He's entering puberty, and like humans of a similar age, he's going to be a real handful for about the next four to six months. The circling and spraying are both signs of it.
Don't despair, you'll both pull through it.
As to whether or not you should have him neutered, you'll probably get some contradictory advice here. Unlike female rabbits, where there are very good medical reasons to have them spayed (ovarian tumors, primarily), as far as I have ever been able to find, the risk of testicular cancer in male rabbits is on the same order as the risk of surgery - which is to say, quite low.
So, it's really more a matter of behavior modification than medical necessity. There's no rush. You can watch and see how Ziggie's behavior changes as he matures.
On the other hand, if Ziggie's spraying gets to be a problem or he becomes aggressive, then by all means get him neutered if your vet says he's old enough.
I had a male rabbit, Scone MacBunny, for seven and a half years, and he was never neutered. He was pretty rambunctious between about six and ten months of age, but I decided to put off the decision until after the Teenage Months, and see how he turned out. His behavior settled down again, and I never saw any reason to put him through the surgery. He lived a relatively long and definitely happy life, and passed away of health problems unrelated to anything a neutering would have affected.
As to the "scratching" - is it more of a digging action? A lot of rabbits will do the digging thing, and it doesn't seem to have a fixed meaning. Scone would jump into my lap and dig, and he usually meant, "I could use a treat about now". When I first got Natasha, her digging meant, "I'm about to pee in your lap, unless you carry me over and put me in my litter box". She hasn't done that since I put a litter box in the corner where she really wanted it. It sounds like Ziggie means, "pick me up, NOW!".
If he's nipping, it's time to nip that in the bud, so to speak. Young buns don't realize that nip-talk hurts. When he does it, give a sharp, loud "EEEK!". That simulates the sound of a rabbit in great pain. He'll most likely jump back, then come back and nip less hard. Keep EEKing until he licks you (bunny kiss), or at least stops nipping - some rabbits don't do bunny kisses. I feel sorry for their owners... Scone was a champion kisser, and so is Natasha.
