Inside or Outside Cat?

My cat is strictly an indoor cat. I doubt it would survive outside anymore. I live close to busy roads and I fear he might be struck down if he's ever outside. He's already used to me putting out his food and water and doubt he will be able to hunt for food outside. He's also a very picky eater and only eats dry crackers and canned tuna. He rejects other cat food that I've bought for him. I have opened the door and let him come out before during winter and he went right back into the house after taking a few steps outside.