Is this freezer safe to keep in a garage?

Yes. It is garage ready and rated for ambient temperatures from -7.6°F to 6.8°F, so it can run in an unheated garage or a hot utility room where a standard freezer would struggle.

Do I have to defrost it by hand?

Yes. It is manual defrost, so frost builds on the walls and shelves over time and you empty it and scrape or melt the ice yourself. A chest freezer with the same manual defrost has the same chore.

How much food fits in 3 cu ft?

About 105 quarts of frozen food, roughly what a small household uses in a few weeks or what a larger household keeps as overflow. Two shelves help, but there are no baskets or door bins for loose items.

Does it make ice or dispense water?

No. There is no ice maker and no water hookup. It is a plain freezer cabinet.

How much clearance does the door need?

The door swings out to about 42.8 inches from the back of the cabinet, so leave that much room in front. The cabinet itself is 22.5 inches deep without the handle.

Is it better than a chest freezer of the same size?

It is easier to reach and organize because it opens like a fridge, and it takes less floor space. A chest freezer holds cold longer in an outage and is usually cheaper to run, but you dig through it to find things.