1. If he can change names then why doesn’t he swap Regina’s, Emma’s and Charming’s names for Rumple, Zelena (two people he doesn’t like) and, since nobody in the main “hero” group cares about her, Belle.
2. If Hook does indeed do that, then it makes Hook like a complete and selfish prat.
Basically the writers have written Hook into a corner where either action makes him look bad.