What weapon proficiencies do these magically created weapons use?

The current discussion about proficiencies for touch spells (see: http://forum.baldursgate.com/discussion/comment/196411/#Comment_196411 ) has got me wondering, what are the current weapon proficiencies for: Melf's Minute Meteors, Magical Stone, Shillelagh (club?), Flame Blade (scimitar is implied), Spritual Hammer (presumably war hammers, but is it?) and what *should* they be, if different?

Also - can a cleric/thief backstab with Shillelagh or Flame Blade (as a thief can with a club or scimitar)? All This has never been clear to me!