The hints button is meant to only be used when you get stuck. The main reason I decided on sandbox is because I enjoy looking for content, it breaks up the game and stops it being an overload of constant text. If I put it on the HUD, people would feel like they should just use it all the time, in which case I might as well just make a linear VN, which isn't what I want.
Same reason why the photoshoots aren't hinted. After unlocking the photostudio, there's only a couple of instances that require you to have done photoshoots and they're only there to remind you to check the photostudio now and then. You don't need to do most shoots as soon as they're available, they can mostly be done whenever you feel like it. Unless you need money, but again I've purposefully not done anything that requires money for a while.
I'm still debating that particular issue of should money be used more and if so, should I add an alternate way to acquire it? If I did do something that requires a lot of money which would make the photoshoots mandatory, I may add in a system of alerting you when there are some available.