I played WHM as my main job on 11 for years and I find it quite funny when people say you use only 10-15 spells max from the list of spells WHM had.
WHM get 68 spells at level 50... Yes there are some spells like Banish which you won't use that much, but I made a list of spells I was using all the time while I was climbing up my WHM:
Cure, Dia, Paralyze, Poisona, Protect(ra), Barwatera, Paralyna, Aquavel, Cure II, Slow, Blindna, Silence, Curaga, Barfira, Shell(ra), Blink, Silena, Sneak, Cure III, Regen, Invisible, Raise, Reraise, Protect II(ra), Stoneskin, Cursna, Erase, Viruna, All teles, Stona, Haste, Cure IV, Regen II, Flash, Protect III(ra), Repose

--- That's 43 spells out of 68. The rest of the 25 spells were other bar-spells which were used on occasions as well (I didn't mention them in my list as barfira and barwatera just seemed to be the two things you would try to avoid before level 50) and the other bar-spells (like barsilencera) were just for certain fights.
Out of the whole list of WHM spells I can name only one spell that I never used and it is Deodorize... (except make fun of a party member).

I think you grow with the spells you get (buy, quest) and I think it would be a great idea to bring such content to 14 as well.