How can i make Logan's, Blake's, and everyone else relations higher?
I think Hyao has sad that branch won't ever allow for romancing Logan. You'd need to go back to the bandit attack on the town and convince Logan not to go after the Bandits (he'll still tell you where their camp is) and then later work with him to shore up the town's defenses.
You can't do much more than that, but eventually Hyao will put in romance options that follow that route.