Sadie seems to be very dominant in her personality. There are a cuple local pups she has grown up with and loves to play with ocassionally. However, she demands to drink from the community water bowl first, and then will dump it with her paw, and carry it away so no one else may drink. Is this something which I should be worried about?
--> So long as the other dogs are not objecting to this I would leave it alone. Dogs do not exist in a democracy and if in their "play pack" she is the alpha and the others are okay with that - leave it be! Trying to mess with it can generate confusion which can lead to aggression. As to in general - -if she is showing a tendency to be dominant (and that is VERY Akita like) then you will have to be cognizant of the potential for problems with dogs who do not know her and/or are not willing to be submissive to her. Dominance to people is not necessarily linked to dominance with other dogs but it is wise to also take measures like a nothing-is-for-free program to start avoid dominance issues.
Also, I have taken her many times to interact with young children, and she does very well, she is very people friendly, but there is one girl who lives nearby that Sadie seems to always howl and bark at when she comes near. She has met this girl several times, I cannot understand why she acts this way towards her.
---> If there is one person/child she objects too when she as a rule gets along with that type of person -- THERE IS A REASON! I have learned to trust my dogs when this occurs. I would simply not push any and even avoid any interaction b/t them.
Lastly (for this post) cats. How can I get her to stop trying to chase them? She will be very good and leave them alone and then suddenly chase them around the house. She does not attack them, just runs around after them and tries to play with them like she does other dogs. Any help?
---> Boy this brings back memories as my last Akita pup, Inori, was like this!. Akitas in general differentiate mine from not-mine very well so likely she will never offer to hurt the kitties inside -- outside or strange cats may be a different story. As to stopping chasing -- to some extent that is normal play and to some extent it likely has a hunt-chase component. Learn her preliminary behaviors so you can catch her before the chase begins. Teach her a good "leave it" command and use that. And praise/treat when she STOPS chasing or fails to initiate chase (ie sees kitty & does not chase). I finally had to teach a MINE command which means leave alone always and then spend a million hours saying MY KITTY NO THAT IS MY KITTY! Now they live in relative harmony to the point my two recent adopted kittens sleep curled up w/her.