How can I see detailed inputs & outputs of one calculator?

You only need to go to Stats and scroll down to the calculator lists. Click on the icon 'data', and you will be forwarded to that specific calculator execution data.

Can I change the titles of the inputs outputs (instead of showing cell positions)

Yes, if you want to title your data (for ex, show 'amount' instead of C3), you need to edit that specific cell at your spreadsheet and give it a name. Upload your excel again and you will see the cell reference is being changed to your preferred text at the stats section.