DamoclesAlpha: When you recruit additional NPCs to your party at Training Hall, how long are they with your party? Do they leave at some point on their own or do they follow player's party until manually dismissed or destroyed for good? If player removes them from his/her party, does this affect his/her ability to recruit new NPCs from Training Hall?
I
never hire NPCs*, but I am very familiar with this game.
1) The Training Hall NPCs will stay with your party until dismissed, they will not leave on their own.
2) Hiring and removing Training Hall NPCs has no effect on your ability to hire new NPCs in the future, other than the fact that you can only have 2 NPC hired at a time (I think if your party size is less than 6 you may be able to hire more than 2 though).
*OK, actually I did
once on my first playthrough to help me defeat the Trolls in the Slums.