Could you give some more information about your workflows? What are you specifically are you trying to acheive?
Both of these things are possible in ArcPad, both editing multiple features and editing multiple layers.
Eg 1. If you are looking at making bulk updates to your data, you can use scripting to insert attribute data across multiple features. This can be acheived using the RecordSet Object with both Shapefiles and AXF data or SQL Update Commands in the AXF only.
Eg 2. You can also capture features in multiple layers. If you select both a line and point feature to be editable in the Edit Menu (Big Pencil). When using GPS, use Capture GPS Vertices Tool to collect a line feature from streaming GPS positions and then use the Capture GPS Point Tool to collect point features along the way. Then, simply use the Proceed to Attribute Capture Tool (Big Green Arrow) when you are ready to complete the line feature.
You can also collect a feature/vertex across multiple layers using custom scripting!
There are many options available - it all depends on your project needs!!
Hannah Ferrier
Mobile GIS Specialist
Maptel