Karma is not linear. You can rise or fall, progress or regress throughout time. Hinduism itself even in the most literal sense is cyclical. Everything is reborn and remade unless you break away from the cycle of this existence and achieve Enlightenment. They don't call Samsara the wheel of life for nothing, hell it's even on the Indian Flag.
I see you're diving into Shrodinger's vision of multiple universes/outcomes, which of course is an interesting debate in and of itself, but ultimately we perceive that a choice has been made which guide our individual thoughts/actions.
Karma is also the main schism between Hinduism and Jainism. Hinduism believes in gaining 'good' karma to attain nirvana while Jainism believes in shedding all karma to realize Truth. Intention plays a huge role between the two as well. How you feel about something, regardless if you act on it, also determines 'karmic value.'