1. .app? It usually tends to name the executable file the same as the .vis file. But you can rename both of them. If you rename the .vis file then you need to make sure you add a line to the config.ini file...
...replace name with whatever you named the .vis file.
Quick note: there are applications available that will let you edit the information contained within executable files such as details & the applications icon. It's a shame that there's no meta embedding section included in the build window to allow for adding custom icons & details.
2. no idea.