For your question 2, you can check out the following tools:
1. Copy Features tool with output of shapefile. Curves will be turned into non-curve with densified vertices.
2. If you have ArcGIS 10 - ArcEditor license, you can use the Densify tool in Editing toolbox. Use the Maximum Deflection Angle or Maximum Offset Deviation option if you have a mix of straightline and curve segments in the same polyline. Make a copy of the original data for comparison - to see the difference.
For your question 1, I am not sure if there is a tool to identify/flag curve segments or lines. But once you have a new output using the above tools, you can use the Feature Compare tool to compare the original with the modified features.
Hope this helps.