right, so I'll start with the first one that hasn't been done
I've already read just about everything you have posted on Tapas, so I can definitely give some insight here, having read the whole thing. Plot's not entirely my strongest point, but hey, I'm sure any feedback is helpful, so I'm rather than analysing your plot, I figured it'd be best to tell you what the elements you've introduced so far are making me expect from the rest of your story, that way you have an inkling of if it's being shown the right way or if you expand on things later on!
What I'm expecting from your novel right now is a strong romance plot running straight down the middle, which circles around Helianthus coming to terms with the fact that he is, in fact, a damn good leader, and learning how to utilise that properly. There is also the matter of why the sun's come to earth, which is a juicy little bit to expand, although I can't comment on if it's going to expand into major plot beats or not yet.
Any subplots, I'm expecting to be immediately related to these characters, and I'm getting that kind of ~sense~ that each of these select characters you've introduced will have a direct impact on Helianthus's story. I don't know how long you're expecting this to be, but if it's running on the longer side, it might perhaps touch on these invaders who attacked the city, but I got the feeling that's a threat on the backburner, potentially coming into play toward the end as a catalyst for the romance plot or Helianthus's character development, but I wouldn't be annoyed if they don't actually come back.
Of course, if this story's going to be more along the lines of 100+ episodes than 40, you have a lot more room for introducing these individual threads. I'd hope to see more of the gods along the way, and more of the Sun's struggles because he's clearly got some very human-esque anxiety about stuff. From what I've seen I'm expecting a plot to bloom nicely, but of course I can't comment past your act 1!
(sorry this turned into an absolute wall. also i agree your descriptions and prose and characters are very good, I enjoy them, i also have a good sense of the world around them and the dynamics of this little village)