If I recall correctly, nowhere in the Indiana laws does it say that handguns must be carried concealed. I know it is very rare for people to carry openly, but I do not think it is illegal, but you might get hassled. You might check with the State Police. [url]www.ai.org/isp/contact/index.html[/url]
I have contacted them with firearms questions before, and they seem willing to help.
As far as off limit places, I know that schools and locations being used for school activities are off limits. The riverboats are also off limits. Courthouses might be on the list too. I know that cities are not allowed to make their own laws. If you want to check up on the laws yourself, the entire Indiana Code is searchable at [url]www.in.gov/legislative/ic/search.html[/url]
Hope that helps.