Well, unfortunatly if she neuters him then he can't be shown- he's being show in conformation classes, correct? They must be intact for breed classes.
IMVHO, I would pass on the girl. I know what you mean, its hard to pass up a sweet girl being handed to you, but you just listed a LOT of faults, preventing her from being what you wanted her to be. If you were getting her as a pet, then theres nothing wrong with those faults, those are just her little imperfections that make her unique, and her. But, if you are looking for another show dog, and you only have limmited room, as most of us do, then perhaps it is better to wait and save money for the pup you want. That would also give Titan some time to get adjusted to the idea, and for you to get him a little more socialized with other dogs. Plus, with Maya coming back, it will give you more time to focus on Maya and Titan's relationship without the added stress of a dog totally new to the household, and a dog that's not housetrained or leash trained and is huge!
How is he in the ring? He doesnt really sound aggressive at all, just doesn't like his space being invaded which is completely understandable .