I actually think Belle would help motivate Mr. Gold to accomplish whatever he’s trying to accomplish. However, it’s tricky. Love tends to…what’s the word…unhinge people. So, Mr. Gold is going to have to be very careful. Which is why I partially support his new “alliance” with Regina. If he’s able to infiltrate the inner workings of Regina’s plan, as well as gain her trust, then he’ll have the upper hand. Besides, I kind of think he already has the upper hand. It’s his curse. It’s his creation. And there’s also the possibility that Rumpel gave Regina the wrong ingredients to the curse.
I have a theory that True Love was the key ingredient in the curse, not the heart of someone you love. Regina did manage to cast a curse, but maybe it was the wrong curse, or a different curse. Something obviously went wrong because people keep remembering who they are. Even before Emma came into town. The Mad Hatter, Henry, and possibly Belle. I think Regina miscast the curse.