First of all going pure class you will lack stats in endgame so you better take some support class. If you will decide to go cadence then good support can be shaman with Feral Hunger, Heart of Oak and (if you wish) Wendigo Totem. For forcewave arcanist might be better. Pay attention to the fact that forcewave is a spell actually, so it depends on cast speed not attack speed.
Haven’t try 2H cadence after release yet but read it is kinda ok. But I wouldn’t invest in both cadence and forcewave, pick one of them and max the whole line.
Without Tremor it’s 140% weapon damage + stun + other damages, once every 3s.
With Tremor, it’s 70% weapon damage without stun + other damages, 1-2 times per second (based on cast speed) at 1/3 manacost. So 3-6 Forcewaves instead of one.
For 2H there isn’t really much option other than Shaman, unfortunately. The Shaman 2H melee skills like Brute Force, and Feral Hunger are not only great but there’s nothing else to replace them with. Savagery is also really strong. None of the other class trees offer much for 2H Melee.