2 Newbie Questions:

Question 1

Does toughness cancel redirected damage? In the rules it is written that redirect damage occur after assigned damage step but before applied damage step, at the same time as toughness, which is not making sense to me.

Lets say you have two opposing units and both have one power and one toughness Opponent A is redirecting damage to opponent B.

Is opponent A redirecting 0 damage because his toughness has absorbed the damage?

Is opponent B taking 2 damage, reducing it by one because it has toughness 1?

Can you cancel redirected damage with toughness?

Question 2:

If you use a card with a leaves play trigger action, like zhufbar engineers, as a development. does the card trigger its leaves play condition when the development leaves play? Could I, for example, put out zhufbar engineers as an development, play "long winter" to put it right back up in my hand and trigger its leave play condition so my opponent must sacrifice a unit?

1: Toughness and Redirection take place at the same time, so you choose the order. Toughness does work against redirected damage (not against moved damage though).

In your example, your opponent could choose whether he wanted unit A's toughness or redirect effect to kick in first. If it's the toughness, the damage is canceled and nothing gets redirected.

2: Cards leave play as whatever type they currently are. Zhufbar Engineers says "When this unit leaves play ..." so it won't trigger if it is a development and leaves play.