1. Draw an arc (wall or line doesn't matter). Goto its properties and you can check "Center Mark Visible" if you need to dimension to the center point of an arc.
2. Callout a dimension and go to the dimensions properties... Edit/New... and play around with the Read Convention parameter. You'll notice you can now orient dimension text.
3. Shift + Nudge moves 10 times as far as Nudge.
4. Highlight Sheets (all) in your project browser. Now hold down Num Lock and press the Asterisk (*) key... or hold down Num Lock and press the minus (-) key. You'll notice the Sheets tree expands and collapses.