I have six rats, four girls, two boys. At one stage I had 37, as all three my females had 11 babies each, but one didn't like motherhood, so one the others got 22.
Yes, males smell more than females, but well handled or docile males will sit for hours with their owners, females not so much.
Also, you
must have more than one, as rats are social creatures.
On the biting part, I can honestly say I've only been seriously bitten three times, once on the finger while I was feeding one of them thickened cream (she was a bit greedy) & the other two times on the nose when a feeding mother jumped at me (my fault really). The other two dozen times were by five teething baby rats which used my hand & fingers as a chew toy, gave their mums a break though.
Rats are a good pet of choice, for obvious reasons, cute, smart, loving, not easily spooked, etc... But they are also quite daring, sometimes to a dangerous degree, e.g I have one rat that chases the birds (tries to) & walks up to the cats when they are sleeping & bites their toes/paws, until they either hit him or run off. Just something to keep in mind.
As for the teeth being trimmed, not needed, providing you feed them on hard pellet foods which wear the teeth down, keeping in mind they still need variety, so raw veggies, like carrot, potatoes, lettuce, etc, & even dry dog/cat food is enjoyed. Cereals, grains, seeds (sunflowers, yummy

) are also good, even as a treat or energy boost. Fruit too, all rats like fruit, apples, pears, peaches, & so on.
However, do not feed them tomatoes, cabbage, garlic onions or highly acidic foods, as these can cause upset stomachs & even kill the rats.
Cheese isn't very good for them (surprise), due to its fat content, may cause health issues. Meat can be given occassionally, but may cause some to chew the ears, tail or feet off others. Boiled egg is better.
They do live on average 3 to 4 years, but they often live beyond that if taken care of. Also, rats that breed often or start at a young age will have shorter lives, but they can live longer if not bred with &/or given a long time to get back into shape.
One of my friends just lost a rat at nearly six years old.
Not very pricey, but the cages can cost a bit. Larger the cage, the better, but small cages are okay, providing the rats will be allowed out for excerise.
Careful not to get mice cages, as those are too small for two rats.
That about covers it all, one last thing. Rats are like little dogs, they will learn their names & tricks, but can also be quite loyal. My rat Rico is a good example, he'll choose me over everyone else. They can learn bad habbits though, so you must curb those asap.
Pretty sure I've covered most of it. Pm me if you have a Q.
Also, Darkngorgeous, he looks so cute, he a hooded?