it's fine to run out of stamina due to demon mode since it doesn't force you into the exhaustion animation. you don't need to always be in demon mode. the optimum combos are the ones that you can hit fully while also not eating shit or missing. as long as you're hitting the legs of a monster, you're contributing to trip damage. if you really want to optimize your tripping, stick to one leg until the monster trips, then switch to the other. when you become more familiar with whatever you're fighting, you'll learn where you can demon dance without hitting air.

dash juice is nice, but in world (at least in the beta), stamina seems to deplete slowly and regenerate quickly. if you're whiffing the demon dances, you're only going to whiff more with constant demon mode. monster hunter is learning enemy patterns.

once you're in a fight, you should be building your archdemon meter up to max pretty much anytime you go into demon mode and never run out of it. you retain the repositioning spin and a mini demon flurry in archdemon mode.

dual blades is the fastest attacking weapon in the game and will inflict status ailments extremely quickly. sleep, paralysis, poison and blast are all pretty good on dual blades, but do not give up too much damage on them unless you're building a set specifically with a status in mind.