Crate-training is one of the most important basic training that a dog has to be taught. From your story, it looks like if you're gonna start crate-training your dog, it'll be from zero, and THAT'S OKAY. Many dogs learn basic trainings so much later in life and they can. The 1st few nights he might react by whining, crying, or even biting the crate. When I 1st crate-trained my pup (he was 7 1/2 w), he cried ALL NIGHT the 1st 2 nights. But tough love WORKS. He's learnt that by crying and whining, he doesn't get attention. Don't forget to PRAISE him like crazy everytime he goes into the crate calmly. He needs to be rewarded EVERYTIME he acts accordingly. It's okay to ignore, that's called a learning process. When he's successfully trained, and I hope he will be, it'll help diminish any separation anxieties and you will have an independent but loving dog. Good luck!