That poop looks pretty normal to me! Macaws tend to be messy poopers, and I find it is usually more runny that other species.
As for diet, I would highly recommend getting away from seeds and putting him/her on a pelleted diet. There are many good ones out there, but I am quite fond of lefeber and harrisons. They can be a bit more expensive, but I generally find you feed less and it lasts quite a while.
Supplementing with fruits and veggies is best, and you can even offer things like whole nuts (walnuts, almonds, pecans, etc). You don't want to give too many nuts as they are high in fat, but a few with a meal is perfectly ok. Cheerios also make awesome treats, and they are relatively low in calories.
I would hold back on the cooked meats, as it is much higher in protein than needed if they are on a pelleted diet. In fact, pelleted diets often have quite a bit of protein in them, so that is why it is so important to supplement the diet with fresh foods.
Pasta is very high in carbs, and not such a great thing. It can lead to obesity and really doesn't offer much nutrition wise. Things like sunflower seeds are EXTREMELY high in fat, and can really do some organ damage over time.
Getting a bird to switch to a new diet is not always easy, and I recommend doing it very slowly. Start by mixing in some pellets with the diet he/she I eating now. Over time, slowly increase the amount of pellets. Parrots need to know that what they are being offered is food and they will not eat it if they don't know what it is. I do recommend measuring the food so that you can gauge whether or not the parrot is eating it (Or you can see if there are crumbs in the bottom of the dish).
Drache gave some great advice. There are also tons of great parrot recipes online for veggie goodies! If you are on facebook, I recommend "liking" Bird Tricks. They have awesome articles about pet parrot care, and they often post parrot recipes. You can also ask questions and get wonderful responses.
As for behavior, handling the bird is great for both the bird's mental health and your own! The only thing I caution new owners about is letting the bird on your shoulder. Many birds tend to get emotional every now and then (Especially during the spring) and you just never know when they will have a bad day. With a large parrot, eventually an owner will get bit. Allowing a parrot on your shoulder can definitely increase the risk of a bite to your face. Even the best birds in the world can get spooked or upset, and their target is usually the first thing in their reach, which may be their beloved owner. Another tip is to read about sexual behavior in birds and try to limit these behaviors when interacting wit the bird. Many times owners can unknowingly exhibit "flirty" behaviors towards their bird, and this can lead to an unhealthy relationship between bird and owner.
If you would like to get your bird sexed, there are some great resources that you can send a feather to and have them sexed. It's usually about $15 or $20 and is extremely accurate.
As for diet, I would highly recommend getting away from seeds and putting him/her on a pelleted diet. There are many good ones out there, but I am quite fond of lefeber and harrisons. They can be a bit more expensive, but I generally find you feed less and it lasts quite a while.
Supplementing with fruits and veggies is best, and you can even offer things like whole nuts (walnuts, almonds, pecans, etc). You don't want to give too many nuts as they are high in fat, but a few with a meal is perfectly ok. Cheerios also make awesome treats, and they are relatively low in calories.
I would hold back on the cooked meats, as it is much higher in protein than needed if they are on a pelleted diet. In fact, pelleted diets often have quite a bit of protein in them, so that is why it is so important to supplement the diet with fresh foods.
Pasta is very high in carbs, and not such a great thing. It can lead to obesity and really doesn't offer much nutrition wise. Things like sunflower seeds are EXTREMELY high in fat, and can really do some organ damage over time.
Getting a bird to switch to a new diet is not always easy, and I recommend doing it very slowly. Start by mixing in some pellets with the diet he/she I eating now. Over time, slowly increase the amount of pellets. Parrots need to know that what they are being offered is food and they will not eat it if they don't know what it is. I do recommend measuring the food so that you can gauge whether or not the parrot is eating it (Or you can see if there are crumbs in the bottom of the dish).
Drache gave some great advice. There are also tons of great parrot recipes online for veggie goodies! If you are on facebook, I recommend "liking" Bird Tricks. They have awesome articles about pet parrot care, and they often post parrot recipes. You can also ask questions and get wonderful responses.
As for behavior, handling the bird is great for both the bird's mental health and your own! The only thing I caution new owners about is letting the bird on your shoulder. Many birds tend to get emotional every now and then (Especially during the spring) and you just never know when they will have a bad day. With a large parrot, eventually an owner will get bit. Allowing a parrot on your shoulder can definitely increase the risk of a bite to your face. Even the best birds in the world can get spooked or upset, and their target is usually the first thing in their reach, which may be their beloved owner. Another tip is to read about sexual behavior in birds and try to limit these behaviors when interacting wit the bird. Many times owners can unknowingly exhibit "flirty" behaviors towards their bird, and this can lead to an unhealthy relationship between bird and owner.
If you would like to get your bird sexed, there are some great resources that you can send a feather to and have them sexed. It's usually about $15 or $20 and is extremely accurate.