1. He can mess with people's minds to affect their perceptions. This essentially translates to hyper-realistic illusions with no real tell. Can he control your character's senses in this way? Yes except for America's perception of his people.

1a. If he can't, what's blocking it? Inherent nation-ness, basically.

2. If pushed, it's entirely likely that he'll try to use telekinesis to defend himself or otherwise fend someone off. May he do this to your character? Yes

3. He has a tendency to wander around invisibly and intangibly when he wants to be left alone and to turn invisible or intangible when he feels threatened. Can your character see/affect spirits in any way? No

4. Teleportation. Unlikely, but is there anything about your character that prevents them from being teleported? Alternately, can they anchor him so he can't pop off to the other side of the tower? No

5. It's vague, but canon hints that Testaments have some ability to read a character's will to find out what motivates them. Can he do this to your character? Yes

5a. If yes, what is their primary motivating emotion? the desire to help his people, basically

5b. If no, why not? N/A

6. Tying into his ability to manipulate senses, does your character have any extra senses he'd notice? Nation sense! Basically America has an inherent connection to the land (though for tiny America it's just the colonies right now) and his people and he can always feel it. He can also tell who's a nation just by feel.

7. Anything else you think is worth mentioning? He's usually around England, who does have some magical abilities and stronger capabilities than the baby