>sigh<
If you raise it from a chick it will imprint on humans. Also, living with you it will not learn how to find/kill food in the wild and will not learn how to get along in a flock of its own kind. Raising an animal like that from a baby and then releasing it is cruel. Please do not do this. Either have a pet or don’t have a pet.
Keeping crows or ravens in the US is illegal (migratory bird act, as mentioned) unless you have a crapload of permits.
You really need to be better educated as to the diet of a bird like that before you acquire one. Yes, they can eat just about everything we do, on the other hand, humans often have pretty crappy diets themselves.
Yes. They are capable of learning to talk, though not as adept as some of the parrots.
No. As mentioned, if you raise one from a baby it will imprint on you and will then have trouble going to a wild flock. They are NOT a short term pet! They live decades.
I am concerned because I am not sure you are as informed as you should be to be the owner of a bird of any species. Please educate yourself on your species of interest, as I’m sure you’d want to provide a good diet and environment for any pet. You might try contacting a local wildlife rehabber who might point you to opportunities to actually work wild birds, including crows and ravens, so you can first of all get a better idea of what they are actually like, and second, learn how to properly care for such birds.
You might also try to befriend your local crows. As pointed out, crows are quite intelligent. They also have the capacity to recognize individual humans. If you provide a hospitable environment in, say, your backyard to attract crows, and conduct yourself in a non-threatening manner they will become accustomed to you and even, perhaps, approach and interact with you. Again, this will allow you to become familiar with the species prior to taking one on as any sort of pet.
I will also caution you that social birds demand attention. A LOT of it. MUCH more than most pets we humans have. They can also be extremely destructive. They will chew things up, tear things apart, knock stuff over, get into things…
Please do learn more about birds in general and specific species before taking one as a pet. They can be wonderful creatures, but they aren’t dogs and cats, they aren’t even mammals. They have very specific needs and there are pitfalls to ownership.