Regarding the Noble/Tyrant and minion summoning.

Why don't you treat the minions similar to a wizard's spellbook? Something like this:

Entourage (ex): A Noble has a cadre of loyal followers/servile minions/expendable slaves.

A Noble begins play with 2 1 HD commoner minions plus 1 more per Charisma Bonus. The minions are of any race with no level adjustment and have typical ability scores for their race. These minions follow the Noble and are completely loyal to him, even to the point of death. However any lost minions can only be recovered in a civilised area at the cost of 5 gp each. A Noble can have a maximum of 1+Level+Cha modifier of Hit Dice in minions at a time. Any equipment used by the minions must be provided by the Noble.

At 3rd level, the Noble can hire more capable minions. His minions can now be of a race with a +1 LA or gain a 2nd HD. He may hire Experts (with at least 2 skills of the Noble's choice at max ranks) and Warriors (with at least 1 Fighter Feat that they qualify, of the Noble's choice) but each Expert and Warrior counts as having +1 HD for the purpose of total minions and costs 40gp to hire.

At 5th level, the Noble can hire even better minions. His minions can now be of 3 HD each, or have a Level Adjustment of +2. He may hire Adepts (with at least 2 spells of the Noble's choice and an Item Creation feat that they qualify, of the Noble's choice) but each Adept counts as having +3 HD for the purposes of total minions and costs 100gp to hire.

So every odd level, the Noble gains access to the next level of minions that he must pay for, just like the wizard has to pay for new spells.