Like any world it wouldn't be constant happiness and harmony all the time, but beneath this utopia there wouldn't be any dark shadows (unless it's Luna scaring the children on Nightmare Night!); what you'd see is what you'd utterly get. Like anything it wouldn't be a 'perfect' world. But it'd be a damn sight better than the one we live in now.
There's always the fear, however, of globalization; that is, our tech and culture gradually subsuming/overtaking that of Equestria. There would need to be firm boundaries set to avoid something like that. Celestia would have to put a hoof down at some point during the early years and say, "Right. We can have human tech/food/clothes/customs, etc. up to a point but then that's enough!" But then... if Celestia restricts human stuff you'd probably have pony smugglers getting it in anyway; likewise if Equestrian goods or whatever were restricted human and pony bootleggers would get them to you...
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As he delicately ran a hoof over the shining paintwork of the Gardner Douglas Cobra replica, the pony Speed Demon whistled in awe. "Damn, man... how the bucking hell did you get something like this here? I thought Celestia restricted these..."
As he carefully made some final adjustments to the engine, Grease Monkey turned to his human assistant and grinned. Then, returning his attention to Speed Demon, the mechanic-pony answered, "Me and my bud here, we smuggled it over, one piece at a time. Also helps if you classify it as a 'cultural artifact', or part of your house... heh-heh... Anyway, what you think, man...? She's fully serviced, loud, and has loads of power fo' loads of fun at the track. She's been modded a lil' fo' ponies of course; you can see that by the bigger driver and passenger seats. Got a hoof-conversion kit out the back if you're interested..."
Speed Demon - whom could barely stop himself from drooling at the thought of owning this beast - gave a shaky nod of his head as he replied, "You bet your greasy mane I'm interested! How much?"
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Real crime - drugs, rape, murder, kid/foal-napping, etc - would be very, very low in my world; ponies and enlightened humans take a very dim view of that and it isn't done anymore; the only 'crime' here would be the bootlegging/importing of 'restricted' or 'illegal' human and pony goods, like this for instance...
Guns and other weapons would be heavily restricted for military use only and even then sparingly if at all. The uni-corps has mages with all the human military now; don't need to actually kill someone when you can heavy-tranq them and then deal with them fairly later. Hunting of animals is utterly forbidden! DO NOT EVER try to hunt. You will make Animal Warden Fluttershy angry. You won't like her when she's angry...
Crime. If you do it you will aid the one you wronged. Steal bits and the amount of money you stole will be docked from your pay, or you'll work and your pay for the amount you stole will be given to whomever you wronged. Steal an item; you will buy a replacement for what you stole. If it's a big item, or some other crime... Be prepared to become a servant/butler/gardener/worker for the one you wronged, for the rest of your life if that's what it takes. This is to teach "this is wrong" and to discourage crime. Never to humiliate or shame a criminal. Who knows... you might just end up making a friend, or becoming part of a family. Remember the words from the Golden Record: "To teach if we are called upon..."
For the worst, of worst, of worst crimes... (a tiny bit of TCB here, sorry) the Princesses can permanently turn a human into a pony foal to be "raised again" and given the ultimate second chance; likewise a Pony Criminal can be permanently made human. But as I stated, that's only for the absolutely irredeemable crimes; when there's no other choice, and it's not something done lightly, there's no happiness or glee; there's much heartache and emotion for all involved...
Heavy are the Heads that bear the crowns...