There are characters where playing with a ranged weapon and a spear makes plenty of sense. This is something minor, but this could help me stay with both hands on the keyboard for longer. How about the following key combinations to quickly swap to a given skill set?
Shift + 1 - Skill Set #1 (Ranged Weapon)
Shift + 2 - Skill Set #2 (Spear)
Shift + 3 - Skill Set #3 (Basic Skills)
Now I have to grab the mouse cursor and click the "up" and "down" that changes the current chosen skill set. This is slightly inconvenient, but I can live with it.