I am not a macaw owner but I have experience with them..

1. Can't answer. Never was a macaw owner and I used to want a Greenwinged very badly but decided against it for VERY good reasons!

2. YES. YES. YES. Macaws SCREAM. I don't know if you've ever heard macaws scream but I volunteer at the zoo and you can hear our two pairs 50 ft away. To keep their screaming at a minimum, you'll have to interact with them in every way possibly and incorporate them into your daily life. Many macaw owners wake up with their birds, get ready with their birds, shower with their birds, etc. Macaws are more like puppy dogs/two year old children than birds. They need and thrive on attention.

3. Yes, you can take your macaw outside, but please visit an avian vet beforehand and buy the proper equipment. They have specially made birdie harnesses.

4. Yes, they can/do bite and they bite HARD. Remember, they use their beaks for cracking open nuts. Just imagine what that can do to your hand, yikes! You must "train" (yup, birds need training, too) your bird to accept you as the head of the flock and please socialize it!! Macaws have a tendency to be jealous of their human so you are advised to bring it to different places and constantly socialize it.

Like I said before, macaws are more like puppy dogs than birds. Just imagine a puppy dog with a bone crushing beak and covered in feathers and you've got yourself a macaw I personally would not take this macaw if I were you. If you really want this macaw, please buy and read : Guide to a Well-Behaved Parrot by Mattie Sue Athan

Macaws go through a stage known as the terrible two's. Because your macaw is only 3 months old, you'll have a bit of time to brace yourself and help shape your macaw into a friendly, social bird.

Have you had a parrot-type bird before? A macaw may be too much for you right now, but if you're really dead-set about this, kudos to you and please share pictures!

Edit: Very important question - Was this macaw handfed??