This is a really interesting post which touches on a bunch of different themes in the Sugar Bowl. You know you fucked up by advancing her 50% of the Sugar in advance and before intimacy, but since you don't seem concerned about the $$ and that's not really the gist of your post, so it doesn't really make sense to talk about it at length... other than to say, for most all ppm arrangements, the $$ is NEVER given until after you all do the deed.
The real point of your post is to ask if you can have a "real" relationship in the Sugar Bowl and my general answer is NO. It's not impossible, but it's also not really the reason that SA exists for.
By design, the Sugar Bowl is supposed to be for NSA FWB arrangements... and a "relationship" is a "string" that these girls DO NOT WANT for the most part. Connection?... yes, definitely. Friendship?... yes, probably with the right girl(s). Relationship?... NO.
I am like you in that I love the Sugar Bowl bc it seems more organic and "connections" can seem more authentic and seem less contrived than the hobby. That being said though, I think the best you can hope for from an arrangement is a mutual respectful friendship rather than a "relationship". Relationships come with strings and those come with feelings and feelings complicate things. Most SBs are looking for some casual fun in bed to go with some income and spoiling that they wouldn't normally get from their loser boyfriends. Expecting a relationship from them is unrealistic imo and you are setting yourself up for disappointment if you go in looking for a relationship. There are girls who's profiles say they want a longer-term relationship, but if you are already married, I think you might need to reexamine what you are looking for and how much you can give to a real relationship anyways (probably not much).
My advice to you would be to continue in the Bowl but not put so many expectations on things. Be casual. Enjoy some fun dates with some variety. If you find another SB that you connect with, by all means continue to repeat with her, but understand she wants something casual with no strings and honestly that's what you should want too. It would be great to find a cool hottie to have friends with benefits with... but just keep it at the friend level. She's not your GF and she likely doesn't want to be so don't force that on her. You can be yourself and be genuine without putting false pretenses or reading too much into things.
GL
-jungle