It seems the more I think about systems that will need to be implemented to get to a complete 5e players handbook version of the game. The more I notice there are two distinct ways to go with it a more fast paced story mode, and a slower tactical focused mode. For instance the current reaction system is to toggle to use reactions automatically. Though with a limited number of spell slots in the game. Your going to want shield to be used to avoid the big hits, and not the one the average goblin hit. Though the current system will see you blowing spell slots to avoid a 4 damage hit from a goblin. The only real alternative is to have a system that pauses combat, and asks the play to use the reaction or not.
Given that a player has reactions to use it will slow down the game immensely. For some this will be an annoyance, but for others only being able to toggle your reactions will be equally annoying. In the end you either design your game to favor one play mode over the other, or split the game into two distinct play modes. A story mode could be designed for more fluid story driven play through, and a tactical mode could trade a slower combat system for more control over the combat. Not sure how feasible this is based on the games current design, but it would certainty help with the divide in how the game is designed.
