The answer is yes
1. If you use the "slideshow" option instead of "3D Cube", images will fill more of the screen and will always be shown the right way up, though, if I recall correctly, portrait shots don't work very well here. If you go into standard view, and create a smartlist under Playlists called "3D Visualization Images" (without quotes) then these will be the pictures used for the slideshow/cube 3D vizualisations. You can use the smartlist rules to only list landscape images, as well as add any exclusion or inclusion rules you like, then forget about it. As you tag future photos, they will either fall into the list or be excluded depending on your rules.
2. If you start playback of music first, then go to your image library and browse for some images to play, and play them, the slideshow will run without interupting the music. When going this route, the "Start, Stop, Previous and Next" buttons all act on the slideshow, not the music.
3. The attached image shows my choices under "Photos" in Theater View. "Pictures + Music" opens a playlist group (set up in standard view, then configure theater view to use it) that contains a half dozen or so select smartlists that include a bunch of randomly ordered music and photos. Selecting one of those launches the slideshow and the music together, and here, the "Start, Stop, Previous and Next" buttons all act on the music, not the slideshow. One of my favourites in here is a selection of random landscape photos set to some instrumental tracks from my library. You could just as easily set one up to show all your rave photos to a stomping techno soundtrack if that's more your thing!
If you need any help setting up any or all of the above, just ask, it won't be a problem.
That help?
-marko
ps. love your avatar... "Can't we get you on Mastermind, Sybil? Next contestant - Sybil Fawlty from Torquay, specialist subject: the bleedin' obvious."