Normally people hotkey the different spells they have for a hero. I understand that if you right click on Arachna's webbed shot that it will be set on autocast. Can you "hotkey" a right click on a spell as in this case so that I'll have a hotkey to turn autocast on and off?
Not a good solution. This just turns off single cast - critical for harassing in early game as it doesn't draw creep aggro.
Playing this game is more fun when people are nice to each other.
Support your team, communicate, and have a good game because of it!