Quick and Easy Questions (please read the OP)

[Handsome Jack]

I assume you mean this:

Reserve a pre-existing character as an NPC or third character. For now I'm going to limit this at twice per player maximum. If you just want a character for your personal use, not as a storyline boss or whatever, you can reserve them even if they're outside of your character's canon. Normal NPC usage rules apply, someone might be able to join as the character later.

If you decide to reserve them as NPC Primes then yes. They can summon Secondaries. The points would come from YOUR pool, however.