I think it would be very good to have a DC recommended portable apps, maybe even their own build of it. That is if it doesn't interfere with some copyright or other legal thing that we are unaware of.
I still think this is harder than it needs to be and my experience with LBC last night wasn't all that great. for one thing it kept locking up on me. I am on XP pro sp3. but that is another post.
The cool part of LBC of what I could tell in the online helps is you can have more than one instance of it running.
I run portable apps from the file manager also but sometimes takes some looking to find the right one, hence a launcher for it.
It doesn't matter whose launcher you would use for portable apss, Liberkey or PortableApps, they will install stuff by default you may not want. So a custom made DC build??