With the extensive list of features that currently exist in RPG Engine, I believe you will create gameplay with more depth than GTA.
I also desire to switch between First Person, Third Person, and Other perspectives...
the challenge with this type of camera system has been Projectile Weapon Systems using Center Screen Targeting to fire projectiles.
To properly aim and target weapons from other perspectives, a means to spawn Projectiles from Weapon’s Barrel for proper aiming is required.