You don't click alot at ivys you just click and avatar cuts be himself just like ordinary trees and you click alot in sawmill and about mixing thing...You are right there
Woodcutting takes time i'm 97 now and am cutting at ivys, i say they are best woodcutting xp beacouse you can ruin planks at sawmill even at high level,belive me i tried it and it didn't work...And you can bring a Beaver (the summoning familiar) it gives aa 2 level invisible boost .