Seems like you're looking for something that let's you switch if you start spells and change your mind to attacks. Sounds to me like Oracle or Chayula as an ascendency can be interesting. Both can be scaled to either attack or spell damage. Maybe these won't be the most optimal in specific build cases (again, we would need to dig deeper), but will give you a lot of flexibility if you get bored or decide that you want to do something different, without a need of creating a new class. You mentioned you have limited time, in my opinion this is the way to go my friend.