So little to no loss on losing your pretender? Better to kill them off than try to cure their afflictions?

Personally, I don't feel those fit the Category. Neither does Immortality, or anything of that nature.

Lowering costs and increasing starting Dominion are in my mind more applicable. Even giving all human pretenders not on a horse Stealthy would, to me, feel more at home. I would rather see a prevalance of non-human "SC" Pretenders, than lowering the costs so much that it's more cost effective and gem effective to use Rainbows.

Perhaps giving base casting abilities centered around their inital Path might be more limiting and less game changing. Or perhaps a Focus of Magic based on their initial magic. I don't know if it's codable, but certainly better than slapping Immortality on every one and making the end game even more ungodly unbearable for invading forces.