Hi,
Right now the only way to export individual layers is by soloing ; individual export options will be added in the next patch.
Regarding other issues you might have with either ARA or SLP, feel free to share in detail (with your computer configuration) so they can be fixed in upcoming patches. Thanks!
FYI the playback stop issue and 64bit issue in ARA are Cubase issues which will be fixed with the next Cubase patch.