The way I got around the SetupInit dlg hanging around is: in Sequences, I launch the splashscreen dlgs immediately after SetupInit. The splashscreens have Keep Modeless set to False, so they kill SetupInit.
All following dlgs, except for the ones that I want to kill tthe splashscreens have Keep Modeless set to True.
This way the only drawback is that the SetupInit dlg comes up before the splash.
I did not have to use ORCA to set Keep Modeless, but I'm using ISWI 2.01, if that makes a difference.
Yes, there is a way to get the screen resolution - use the GetSystemInfo function and make the splashscreen's condition in Sequences depend on what resolution you get. I use 3 different splashscreens, one for each resolution I cover.
By the way, I found that IS has a weird limitation: you can't make a dialog with width greater than 771! So I couldn't fill the screen if its resolution is greater than 1024x768.
The other problem I'm having is that a bitmap that looks fine in 256 colors in Paint or other graphic editor degrades to 16 colors in IS and looks awful! This is true even if I limit the palette to 16 colors. Anybody have a guess as to a workaround?