Grace is absurdly powerful. She has weaknesses and isn’t invincible, but in a straight-up physical confrontation in which she doesn’t hold back, Grace wins. Angel Nanase would have a chance, but the form would likely advise Nanase to make like the Roadrunner and “meep meep” it out of there.

Of course, Grace probably WOULD hold back, be overly defensive, and put the safety of others before her own, so… Yeah. She might still be in trouble against someone dastardly.

As for the thumb war, yes. Everyone can beat Tedd in a thumb war.