There's no way to not have to re-arrange icons when you install new themes, once you get the theme installed and have moved it all around when you go back to it you won't have to but a new theme you'll have to. No work arounds possible or available. It's a RIM OS thing.
As far as the profile icon goes, you can find themes that don't have the profile icon. That's something that the theme creator will have to do. Sometimes I take it out on mine or make it non selectable just so I have a visual of what profile I'm on. I did that with my bDroid theme I'm using, it's there but doesn't do anything but change to the profile I am on since I use keyboard shortcuts