Err... I think you're not quite getting what Cleric's Stance does. It doesn't prevent you from using certain skills, what it does is swap your INT and MND stats, and additionally apply a 20% damage increase and a 20% penalty to healing.

You should never, EVER heal in Cleric's Stance. As you leveling, the stats will be close enough together that the 20% penalty will be a greater than any benefit you gain from switching the two. It gets even worse in endgame: Since all the INT heavy gear is restricted to just SMN and BLM, and SCH only gets the MND heavy endgame gear, your MND will vastly outweigh your INT. Yes, Cleric's Stance swaps the stats AFTER all bonuses from things such as gear.

So, tl;dr, even if you allocate all your points to intelligence, never heal in Cleric's Stance.