Zoso was only taunting Rumpel so that he would kill him. I think that was made quite clear in the episode. So, I still think Baelfire is his biological son. And even if he isn’t, that doesn’t automatically translate into “Rumpel probably kidnapped him.” The mother probably left him or died. And there are also a lot of theories going around that suggest that Cora may have been Rumpel’s first wife, and if that’s the case, then I’m glad Rumpel raised Bael instead of Cora.
But I’m confused as to why you label Rumpel a coward for running away from war (a war that asks young children to kill), but the criticize him for killing the knights at the end of episode. So, it’s ok for him to kill in a war, but not to kill for his son? Personally, being a coward or refusing to fight another man’s war doesn’t translate into being a coward. Why risk your own life for another man’s war when you can risk it for the life of your child.
And also disagree with your comment about Rumpel “doing evil for evil’s sake.” We all know why he became evil. He’s possessed by the power of the Dark One. Even someone like Mary Margaret or Emma would eventually succome to it’s power.
And of course we don’t what his motivatins are. That’s been done on purpose. It’s not because the writers are confused about his character, it’s because the show needs to last longer than 1 season, so they stretch the story out. He’s hundreds of years old, has a lot history and mythology to tell, and is the creator oft he curse. So naturally, it’s going to take longer to tell his story than the Evil Queen’s or any of the other characters for that matter.