Interesting, never heard of that one, thanks!
Yes, it is of course slightly space-inefficient keeping older libraries around if the programs could be compiled with newer ones. If the maintainer of a program stops maintaining it, you might have to keep older libraries around if newer ones have broken their ABI/API. If the choice is between a functioning program or a broken one, I'll take the functional one and so would anyone unless you can find a replacement, and those can't always exist, especially for games for example.
I wish everything used standardized dynamic paths, like you could have them be an environmental variable, where programs would just query $LIB64 or $BIN64 etc in order to communicate effectively, allowing a system to store files anywhere it wants. Hell, you could make a structure like Windows did if you wanted to, and put all the shared libraries in \Linux, and all the bins and other stuff in \Program Files, hehe. ^^
no launchers in your panel, no additional panels
The panel is the launcher, and it's scrollable when it gets full so that you don't need (but still might like) another one. It's a "dock". A dock is a window switcher + app launcher rolled into one, which is what both Microsoft and Apple made default in their OSes, and now Gnome and Ubuntu. Of course, Linux has had docks long before anyone else.
He has not acquired a fortune; the fortune has acquired him. -- Bion