sweeps to allow your momentum to continue whenever you use an attack that generates a large amount of force, such as an overhead slash, or a twohanded slash. you don't waste much energy, and you actually go into the sweep faster and make it more powerful by adding the momentum of your previous attack to it in addition to it's own momentum
Now, advanced dodging is more of a form of knowledge and skill than anything.
Like I did with you, try and discern the method your opponent is going to use to counter your attack or your own dodging method. Then, have a way that you can turn that dodge into either another dodge, a counter, or a guard if needed.
I had suspected you would simply try and come at me with a horizontal strike, so by punching you with the pommel, I had set myself up in a good position.
Much of Kenjutsu is just being able to react well and adapt to the fight. But, if you can prepare yourself for something, than things will more than likely go in your favor.
Like chess, try and think two moves ahead, if you can.