You have several good ideas.
A few of them are already planed, such as the merchant and companions.
And I agree that the home needs a touch up in terms of graphics.
House expansions: Currently only a dungeon is planned
Adding a prop that shows the current level of corruption in the region is a good idea and will be added.
In terms of an end game screen where upgrades can be purchased depending on how well you did sounds like a good idea as well. I'm not sure how it will work yet and it will likely be while before it shows up.