You asked:
So.. why are you asking questions you know the answer to?
You want all the rewards faster and to be able to just do hunts nonstop for large XP gains as well. That's pretty apparent as well.
Hunt trains involve coordinating with others. Daily bills do not. Considering I don't do hunt trains yet have all the unique items available for nut sacks (god I hate that currency name). I would say they are completely viable, just not incredibly speedy.
All you want is bigger rewards because you want the stuff now AND you want to level quickly while doing so.
I don't think hunt bills need to be optimized because they're not meant to be the grind you're looking for.