The build is certainly not resticted to 1 use of crit immunity. It should have either 3 or 4. assuming it meets the minimum level of 14 WIS. My first BK build was based on this one and certainly had 3 or 4 uses.
Have you visited the spell pedestal and got your 'wands' for the spells. You then have to adjust the wands (speak to them) to choose your spells at each level. The 1 slot of each level is a default until this is done.