hey well if you're thinking about getting into cresteds they're great, very easy to care for, and they breed pretty readily. For you're first question about handling them you can definitely do it but as with most geckos be careful because they can lose their tails, and they don't regenerate them, but it normally doesn't have any long term health effects and they still look cute without them.
For your second question about housing them in a 10 gallon, if it is a baby this is fine but as they mature I would move them up to at least a 20 high. They need a vertically oriented tank because they are climbers and they need plants with nice big leaves for them to curl up in and hide during the day ( they're nocturnal. Also another thing that's great about these guys is they don't need an additional heat source as long as the room they will be in isn't too cold. I like to keep mine no higher than 80. Humidity is a must for these guys, it is best to give them a good spray at night right after the lights go out because they will drink the water drops that form on the leaves.
And for your third question about feeding, I give mine crickets, meal worms, and baby food ( mango flavor is their favorite).
Hope this helps, and you should definitely consider getting one of these guys-they're a lot of fun!