Hi Stephen! Welcome!
You have had some BRILLIANT advice by our other members, and they are all spot on!
EVERY bird will bite you.. EVERY bird will be loud and scream..
The saying is- It isn't 'if' you get bitten, it is 'when'
Not necessarily blood and stiches, just warning bites and little nips or bruises
Your job is to know when your bird is upset and hormonal, and encourage other behaviours so the bird isn't screaming for your attention or wanting to bite you!
Having a bird from a baby "can" help, but it will be all about how you socialise the baby from day one!!

When hormones kick in, it will be alot difficult, but when they are adult, each spring they are still going to get hormonal...
Now i have owned every kind of animal i think, lots of horses, lots of dogs, lots of cats.. Possums, kangaroos, cows, chickens, ducks
NOTHING is as time consuming as a parrot..
They are SO intelligent it is unbelievable.. The bond and love they bring to you is incredible if you care for them right!
The problem with a macaw, is their size.. If you are scared of their size, you are going to have a huge issue... Because they know you are scared, and their beak CAN do damage!
I have had my macaw since he was 7 months, he is now almost 2 and a halfish!
He has neverrr been aggressive to me, because from day one, we did socialising, and training, and i taught him boundaries and i NEVER showed fear..
I don't see his beak as big, i think he is tiny

So he has never thought- oh i am going to try and be the boss of her, i will bite her haha
I love him with all my heart, honestly, i think you will find most bird owners have a difficult time explaining how much they actually love their parrot...
I never thought it was like that, kinda like you... Until you actually get one, and it is just very special
But they require LOTS of room to play, LOTS of toys- I mean they destroy 50 dollar toys in 5 minutes..
And i think it is a minimum of 4 hours playtime OUT of the cage each day, with lots of interaction... Nice healthy diet.. Veges, fruit, pellets, nuts EACH day..
Go and have a play with different birds and see how comfortable you feel with them! If you do love the macaw, and have NO fear from them, and realise you WILL get bitten, then go ahead, just remember lotsssss of training.. Don't allow screaming and attention seeking from the word go and you should be fine for the screaming part, although they will scream no matter what, it is their flock call..
Most days Fargo is quiet, just talks, never screams, unless it is storming or all these crows sit out his window.. He hates crows hahaha
I think training is the key, and ALOT of socialising with people and getting out and about!
This is my boy, see how clever they are!!
[ame=http://www.youtube.com/watch?v=3Y7hr3ZQojc&feature=youtu.be]Fargo the blue and gold macaw incredibly smart bird tricks - YouTube[/ame]
Depending on the type of bird, some may be cuddly, others might just want to sit and be close to you! My macaw sleeps next to me, plays upside down on his back, gets sooo many cuddles and kisses, he is just like a baby!
Can have a look at Fargo's page, there are heaps of pictures of him being silly on there
Hope this helps a little! Although it is just saying what everyone else has said! haha