This should be answered as a survey-type, since everyone and every hedgie is different!
Yes, they are very shy at first, and it can take real patience to get them used to you. but it is totally possible and the first time they "chirp" or purr in your hands, it's so heart-warming
Some are really playful and will crawl all over you and explore and put their nose in everything. others will want to curl up on your lap or in your neck to snuggle. My Fiona (my 1st and only hedgie) will do both, depending on the time and her mood. I have a little "snuggle-sack" that she likes to sleep in while I read or watch tv or something for a while
Yes, they are nocturnal, I have never heard of anyone switching their schedule, but it's probably best to leave it. Fiona, however, has her lights turned off a little later than what I've seen most people, being that she is in my bedroom and my lights don't go off too early. But she still has plenty of play time at night in her wheel. You can take them out during the day and play. They might be grumpy the first few minutes, but they ease. Personally, Fiona will be hyper and running all over around noon, but sleepy and cuddly later on in the day/evening (such as right before I shut the lights). A little counter-intuitive, but shes just weird :P
And no, they really don't smell at all. Of course, her cage should be poop-scooped frequently (like when you see it, often when you wake up). If you have a sterilite bin/aquarium tank (less air flow) the pee may smell more than a wire cage. But generally, they do not smell so long as you keep up the hygiene.
If I could offer ONE piece of advice, make sure you have an exotic vet near by and can afford what can be a very costly visit. I learned the hard way, but was lucky enough to scrounge up some money for a pricey surgery. Between high quality cat food, toys, fleece, and tons of other adorable things you'll see and want, it can add up!