Yes, just set the temperature and the chiller will kick in when the water hits that temp. Although they are much more expensive than heaters.
Water is the same as all fish as long as they've adjusted to the parameters.
Feeding can be anything from once a week to everyday. They can be fed bugs, raw shrimp/prawn, animal heart and high protein fish food. Not all fish will accept commercial foods and most will take awhile to adjust.