As Big Spence pointed out. You gotta tough it out in order for it to make sense. It all makes sense by the end of the current update.
I'll explain the two major plots that you are confused about in a SPOILER AHEAD, so if you want, go ahead and read, but it's better to experience it, I personally think.
Don't click read more if you don't want to be spoiled.
P.S If you don't like VN games like this, then be prepared whenever you see Ren'Py games because most of them center around story. You're better off looking for RPGMaker games. To me, the story is exactly what makes it more distinctive/original compared to other dating sim/harem collector-type games.
The reason the town doesn't like heroes is because the last one that they had abandoned them in their time of need and was a complete asshat (coughLikeLeoncough)
And the reason why all the characters seem selfish for wanting the MC to not leave the town is because it IS selfish. They're human beings. PLUS on top of that, Rebecca pointed out that official Heroes were meant to marry the Lady of the town. To them, they just got a promising new hero, but he's now abandoning them. It's not just to check on your family, you're going back to them. Possibly never to see the town again.