Very nice! I love the idea of Karma as mechanic where the higher it gets the more power but at greater risk. It can be hard to work that kind of dynamic into a game but it sounds like karma would catch it well. Might I suggest the inclusion of kind of a checklist/"if the players do this" or what have you for karma so that a GM has a nice list to quickly consult to see if players gain karma or not? :)
The Requiring a ritual too creates a nice dynamic that encourages planning ahead and preparations since there is still a fail/die state.