Long paths can be searched using the "Custom File Search" of TreeSize, simply activate the search option "Full Path longer than X characters" with a value of 255. In the main application, folders containing long paths are highlighted in red in case the option "Tools > Options > View > General > Show elements conatining path >260 chars in red" is activated.
The context menu of theroot directory offers an option, for removing files that go below a certain limit. Right-click on the root directory and select "Expand > Hide folders smaller than". (alternatively, you can select "Expand" from the ribbon menu "Scan")
Yes, it is possible. This can be done in the options dialog of TreeSize under "System > Startup". You can specify up to five paths here that are scanned when TreeSize is started.
If the root directory of this drive is selected, the drives free space will be shown in the pie chart. Please note that this requires the corresponding option in the context menu of the pie chart to be activated.
You can setup TreeSize to create and email a report daily using command line options. Please see the help file for details.SMTP must be configured properly to do so.
It is currently not possible to send this report only in case of low disk space. For such tasks, please have a look at SpaceObServer, which provides extended scripting capabilities.