1. Generally we'll leave the pacing of that to you, Tamers will be able to manage their own acquisition of other familiars, you can off-screen it if desired, or you can run your own player plots or arrange including them in missions or as part of a major plot depending on your preference.

2. No hard limit, but if the character is a Student we will generally ask they keep to a smaller number since student characters are intended to be more reflective of their "earlier canon" powerset at the start of the game.