The second error you are getting is because of the change you made to the HR profile option. You can put the original value back so that we can focus of the actual issue. Which is the following I believe:
You are unable to see the inventory organization in your Financial Options screen.

This usually happens when you do not fill in the accounting tab for the inventory organization. Could you please upload the images for your inventory organization setup so that I could see if that is ok.

Thanks