What does this offer outside of the official Space Exploration mod? This should also be marked as non-official.

Of course, this is not an official build.
I personally selected all the mods, mostly there are visualization mods, as well as high-speed convoys and loaders. There are no Cheat mods facilitating gameplay, only tweaks

Sure, just change the name so that people know that it's not official.

Firstly, there is an Official assembly of mods for Space Exploration from the creator on the portal. Secondly, in the description of the modpack it is written that this is the optimal assembly, so I don't see any reason to change the name