The Japanese Sonic CD manual described Amy as "optimistic" and "an energetic tomboy" who likes carding reading, fortunes and "mystic things". The big difference between the Classic and Modern iterations is that Classic Amy is 8 years old and Modern Amy is 12 years old. (For reference, Classic Sonic is 15-16 years old and Modern Sonic is 15 years old.) So in the "Classic" lore the idea is more that Amy is a plucky little kid with an innocent crush, whereas in the "Modern" lore Amy and Sonic are closer to being peers. Yeah, Charmy's infinite flight would break the game. They'd have to limit it somehow, but ideally without undermining the premise that he's a bee. Charmy is actually one of the characters I most want to be playable in a Mania sequel - Metallic Madness Zone's shrink ray demonstrated how controlling a miniature character can add a dash of variety to the gameplay, and it would be easy to add alternate paths this way.