Literally nothing incentivizes me to do evil things... well besides doing evil just for being evil. If anything I am penalized for going down that path even though I should probably be incentivized more to be evil rather than good.
First of all, your character should not know what benefits will something gives him to side with anyone ... you can just presume. :P I completely understand the urge of going the most profitable route ... on the other hand, those should not allways be the right attitude.
Also ... yes, you may end up with empty hands, and head full of regrets ... The question is: Is that bad thing? You could choose different path, but you choosed this one, and you choosed poorly. For myself on the contrary, once you get screewed with evil, once you get screewed with good options (for example ungreatfull victim in Hag's house).
As for goblins ... you sided with selfish and toxic beings ... and then acting selfish and toxic ... what else you expected? That seem acurate and i honestly like it that way.
I'm sorry, but do you not understand the point of incentives? What you are saying here is "the evil path is fine because you are supposed to get screwed over in it", so why would anyone ever take it then? This is like saying getting your brain eaten by the dying mindflayer in the Nautiloid's wreckage is as valid as the entire good path...