I quite disagree with the rpghorrorstory feeling. It's the opposite to me, even if I see why you may feel like this.
It's the opposite because the grandiose past comes with two bond that are completely in the hands of the dm, and because it is a video game, there is no bargaining around it : you have an anciant mortal curse that you need to feed in order to survive, and you have a past with a goddess, and we all know how the power dynamic is with a god or goddess.
On the one hand it is quite some for the dm to integrate, but on the other it's even more to work with than a paladin oath, a warlock patron or a cleric god. Narrative bonds are powerful tools for the dm.
As for the writing and the dialogue options, Gale is an asshole at first, that's not bad writing in itself. I guess it could be better, but I'm no writer and I'm not good with talking to people. I find it reasonably good. With some people you can only be blunt.
I think some people are out off balance by the direct flirty behaviour though. It's funny IMO because, although I'm not a woman, I feel like this might be what women live with some men. This is the case for several characters btw, and some articles about how horny the characters can be hint me into this line of thought.