Actually, neither the crescent nor the moon represent Islam. Nabi (SAW) never used them, he only ever used a plain black, plain white, or black/white/coloured flag with white shahdah written onto it.
But anyway I think the latest splash screen is the best...but with a new logo without the cresent or start...
BTW are GDM themes easily changeable to KDM themes? I think it would be best to use KDE for UbuntuME (personal but imho justified opinion) so it would be good if artwork was easily converted and needn't be completely redone.
but masha'Allah, very good work. Glad we have good graphics artists on board

Alhamdulillah
-Rashid