1.) You cannot open a folder
normally from the main window.
Only:
Alt+Enter Show Torrent properties
and then Ctrl+E (Open Folder)
or
First click Show Torrent properties and after that (Open Folder)
2.) Each new torrent file opens a new window of the client,
and certain downloads only work in certain windows.
(When I add a torrent a new instance of transmission is spawned.)
Transmission 3.00+ (Interface + Options) Redesign
viewtopic.php?f=1&t=20666